W. R. Berkley (WRB) 424B5 Prospectus supplement for primary offering

Filed Pursuant to Rule 424(b)(5)
Registration No. 333-249950

The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and are not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

Subject to Completion

Preliminary Prospectus Supplement Dated September 8, 2021

PROSPECTUS SUPPLEMENT

(To Prospectus dated November 6, 2020)

$                

W. R. Berkley Corporation

            % Senior Notes due 2061

We are offering $            in aggregate principal amount of our    % Senior Notes due 2061 (the “notes”). Interest will be payable on the notes each March 30 and September 30 to the holders in whose names such notes are registered at the close of business on the immediately preceding March 15 and September 15 (whether or not a business day). The first interest payment will be made on March 30, 2022. The notes will mature on September    , 2061, will be senior unsecured debt obligations of W. R. Berkley Corporation, and will be redeemable at our option at any time, and from time to time, in whole or in part, at the redemption prices discussed under the caption “Description of Notes—Optional Redemption,” plus accrued interest to the date of redemption.

Investing in the notes involves risks. See “Risk Factors” beginning on page S-4 of this prospectus supplement, under “Item 1A. Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2020, which is incorporated by reference in this prospectus supplement and the accompanying prospectus.

	Price to Public (1)		Underwriting Discounts and Commissions		Proceeds to W. R. Berkley
Per Note		%		%		%
Total	$		$		$

(1) Plus accrued interest, if any, from            , 2021, if the settlement occurs after that date.

Neither the Securities and Exchange Commission (“SEC”) nor any other regulatory body has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense.

We do not intend to apply for listing of the notes on any national securities exchange. Currently, there is no public market for the notes.

The underwriters expect to deliver the notes in book-entry form to purchasers through the facilities of The Depository Trust Company (“DTC”) for the accounts of its participants, which may include Clearstream Banking, S.A. and Euroclear Bank S.A./N.V., against payment in New York, New York on or about             , 2021.

Joint Book-Running Managers

BofA Securities Credit Suisse J.P. Morgan Morgan Stanley

The date of this prospectus supplement is                 , 2021.

TABLE OF CONTENTS

PROSPECTUS SUPPLEMENT

	Page
Prospectus Supplement Summary		S-1
Risk Factors		S-4
Forward-Looking Statements		S-6
Use of Proceeds		S-8
Capitalization		S-9
Description of Notes		S-10
Material United States Federal Income Tax Considerations		S-18
Certain ERISA Considerations		S-21
Underwriting		S-23
Legal Matters		S-29
Experts		S-29
Where You Can Find More Information		S-29
Incorporation of Certain Documents by Reference		S-29

PROSPECTUS

	Page
About This Prospectus		1
Forward-Looking Statements		2
W. R. Berkley Corporation		4
Risk Factors		4
Use of Proceeds		4
General Description of the Offered Securities		5
Description of Our Capital Stock		5
Description of the Depositary Shares		10
Description of the Debt Securities		13
Description of the Warrants to Purchase Common Stock or Preferred Stock		27
Description of the Warrants to Purchase Debt Securities		29
Description of Stock Purchase Contracts and Stock Purchase Units		30
Plan of Distribution		30
Legal Matters		32
Experts		32
Where You Can Find More Information		32
Incorporation of Certain Documents by Reference		33

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This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offering and also adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference herein and therein. The second part is the accompanying prospectus, which gives more general information, some of which may not apply to this offering.

This prospectus supplement and the accompanying prospectus are part of a registration statement that we filed with the SEC, utilizing a “shelf” registration process. Under this shelf registration process, we may, from time to time, sell the securities described in this prospectus supplement and the accompanying prospectus in one or more offerings.

You should rely only on the information contained in or incorporated by reference in this prospectus supplement and the accompanying prospectus and any free writing prospectus filed by us with the SEC. Neither we nor the underwriters have authorized anyone to provide you with different information. Neither we nor the underwriters are making an offer of these securities in any state or jurisdiction where the offer is not permitted. You should not assume that the information contained in this prospectus supplement, the accompanying prospectus, any free writing prospectus and the documents incorporated by reference herein and therein is accurate as of any date other than their respective dates. Our business, financial condition, results of operations and prospects may have changed since those dates.

Notice to Prospective Investors in the European Economic Area

None of this prospectus supplement, the accompanying prospectus or any related free writing prospectus is a prospectus for the purposes of Regulation (EU) 2017/1129 (the “Prospectus Regulation”). This prospectus supplement, the accompanying prospectus and any related free writing prospectus have been prepared on the basis that any offer of notes in any Member State of the European Economic Area (the “EEA”) will only be made to a legal entity which is a qualified investor under the Prospectus Regulation (“EEA Qualified Investors”). Accordingly any person making or intending to make an offer in that Member State of notes which are the subject of the offering contemplated in this prospectus supplement, the accompanying prospectus and any related free writing prospectus may only do so with respect to EEA Qualified Investors. Neither W. R. Berkley Corporation nor the underwriters have authorized, nor do they authorize, the making of any offer of notes other than to EEA Qualified Investors.

Prohibition of Sales to EEA Retail Investors – The notes are not intended to be offered, sold or otherwise made available to and should not be offered, sold or otherwise made available to any retail investor in the EEA. For these purposes, a retail investor means a person who is one (or more) of: (i) a retail client as defined in point (11) of Article 4(1) of Directive 2014/65/EU, as amended (“MiFID II”); or (ii) a customer within the meaning of Directive (EU) 2016/97, as amended (the “Insurance Distribution Directive”), where that customer would not qualify as a professional client as defined in point (10) of Article 4(1) of MiFID II; or (iii) not a qualified investor as defined in the Prospectus Regulation. Consequently no key information document required by Regulation (EU) No. 1286/2014, as amended (the “PRIIPs Regulation”) for offering or selling the notes or otherwise making them available to retail investors in the EEA has been prepared and therefore offering or selling the notes or otherwise making them available to any retail investor in the EEA may be unlawful under the PRIIPs Regulation.

Notice to Prospective Investors in the United Kingdom

The communication of this prospectus supplement, the accompanying prospectus, any related free writing prospectus and any other document or materials relating to the issue of the notes offered hereby is not being made, and such documents and/or materials have not been approved, by an authorized person for the purposes of section 21 of the United Kingdom’s Financial Services and Markets Act 2000, as amended (the “FSMA”). Accordingly, such documents and/or materials are not being distributed to, and must not be passed on to, the general public in the United Kingdom (the “UK”). The communication of such documents and/or materials as a financial promotion is only being made to those persons in the UK who have professional experience in matters

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relating to investments and who fall within the definition of investment professionals (as defined in Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, as amended (the “Financial Promotion Order”)), or who fall within Article 49(2)(a) to (d) of the Financial Promotion Order, or who are any other persons to whom it may otherwise lawfully be made under the Financial Promotion Order (all such persons together being referred to as “relevant persons”). In the UK, the notes offered hereby are only available to, and any investment or investment activity to which this prospectus supplement, the accompanying prospectus and any related free writing prospectus relates will be engaged in only with, relevant persons. Any person in the UK that is not a relevant person should not act or rely on this prospectus supplement, the accompanying prospectus or any related free writing prospectus or any of their contents.

None of this prospectus supplement, the accompanying prospectus or any related free writing prospectus is a prospectus for the purposes of Regulation (EU) 2017/1129 as it forms part of domestic law in the UK by virtue of the European Union (Withdrawal) Act 2018, as amended by the European Union (Withdrawal Agreement) Act 2020 (the “EUWA”) (the “UK Prospectus Regulation”). This prospectus supplement, the accompanying prospectus and any related free writing prospectus have been prepared on the basis that any offer of notes in the UK will only be made to a legal entity which is a qualified investor under the UK Prospectus Regulation (“UK Qualified Investors”). Accordingly any person making or intending to make an offer in the UK of notes which are the subject of the offering contemplated in this prospectus supplement, the accompanying prospectus and any related free writing prospectus may only do so with respect to UK Qualified Investors. Neither W. R. Berkley Corporation nor the underwriters have authorized, nor do they authorize, the making of any offer of notes other than to UK Qualified Investors.

Prohibition of Sales to UK Retail Investors – The notes are not intended to be offered, sold or otherwise made available to and should not be offered, sold or otherwise made available to any retail investor in the UK. For these purposes, a retail investor means a person who is one (or more) of: (i) a retail client, as defined in point (8) of Article 2 of Regulation (EU) No 2017/565 as it forms part of domestic law in the UK by virtue of the EUWA; or (ii) a customer within the meaning of the provisions of the FSMA and any rules or regulations made under the FSMA to implement the Insurance Distribution Directive, where that customer would not qualify as a professional client, as defined in point (8) of Article 2(1) of Regulation (EU) No 600/2014 as it forms part of domestic law in the UK by virtue of the EUWA; or (iii) not a qualified investor as defined in Article 2 of the UK Prospectus Regulation. Consequently no key information document required by Regulation (EU) No 1286/2014 as it forms part of domestic law in the UK by virtue of the EUWA (the “UK PRIIPs Regulation”) for offering or selling the notes or otherwise making them available to retail investors in the UK has been prepared and therefore offering or selling the notes or otherwise making them available to any retail investor in the UK may be unlawful under the UK PRIIPs Regulation.

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PROSPECTUS SUPPLEMENT SUMMARY

The summary contains basic information about us, the notes and this offering. Because this is a summary, it does not contain all the information you should consider before investing in the notes. You should carefully read this summary together with the more detailed information, financial statements and notes to the financial statements contained elsewhere or incorporated by reference into this prospectus supplement or the accompanying prospectus. To fully understand this offering, you should read all of these documents. To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus, on the other hand, the information in this prospectus supplement shall control. Unless otherwise indicated or the context otherwise requires, all references in this prospectus supplement and the accompanying prospectus to “W. R. Berkley,” “we,” “us,” “our” or similar terms refer to W. R. Berkley Corporation, together with its subsidiaries.

W. R. Berkley Corporation

Introduction

W. R. Berkley Corporation is an insurance holding company that is among the largest commercial lines writers in the United States and operates worldwide in two segments of the property casualty insurance business:

• Insurance—predominantly commercial insurance business, including excess and surplus lines, admitted lines and specialty personal lines throughout the United States, as well as insurance business in the United Kingdom, Continental Europe, South America, Canada, Mexico, Scandinavia, Asia and Australia.

• Reinsurance & Monoline Excess—reinsurance business on a facultative and treaty basis, primarily in the United States, United Kingdom, Continental Europe, Australia, the Asia-Pacific Region and South Africa, as well as operations that solely retain risk on an excess basis.

Our two reporting segments are composed of individual operating units that serve a market defined by geography, products, services or industry served. Each of our operating units is positioned close to its customer base and participates in a niche market requiring specialized knowledge. This strategy of decentralized operations allows each of our units to identify and respond quickly and effectively to changing market conditions and specific customer needs, while capitalizing on the benefits of centralized capital, investment and reinsurance management, and corporate actuarial, financial, enterprise risk management and legal staff support.

Our principal executive offices are located at 475 Steamboat Road, Greenwich, Connecticut 06830, and our telephone number is (203) 629-3000.

S-1

The Offering

Issuer	W. R. Berkley Corporation
Notes Offered	$             principal amount of             % Senior Notes due 2061
Maturity Date	September     , 2061
Issue Price	% of face amount plus accrued interest, if any, from             , 2021, if settlement occurs after that date.
Interest Rate	% per year
Interest Payment Dates	March 30 and September 30, beginning on March 30, 2022, to the holders in whose names such notes are registered at the close of business on the immediately preceding March 15 and September 15 (whether or not a business day). Interest will accrue from             , 2021.
Optional Redemption	Prior to March     , 2061 (the date that is six months prior to the maturity date of the notes), we may redeem the notes at our option on not less than 10 days’, but not more than 60 days’, prior written notice, in whole or in part, at the “make-whole” redemption price discussed under the caption “Description of Notes—Optional Redemption,” plus accrued and unpaid interest to, but excluding, the date of redemption. On or after March     , 2061 (the date that is six months prior to the maturity date of the notes), we may redeem the notes at our option on not less than 10 days’, but not more than 60 days’, prior written notice, in whole or in part, at a redemption price equal to 100% of the principal amount of any notes to be redeemed, plus accrued and unpaid interest to, but excluding, the date of redemption.
Sinking Fund	None
Ranking	The notes are unsecured and unsubordinated and will rank on a parity with all of the issuer’s existing and future unsecured and unsubordinated indebtedness.
Covenants	The supplemental indenture for the notes contains limitations on liens on the voting securities of our “principal subsidiaries,” as such term is defined in the section under the caption “Description of Notes— Additional Covenants of W. R. Berkley—Limitation on Liens,” and on the voting securities of a subsidiary that owns, directly or indirectly, the voting securities of any of our principal subsidiaries. The supplemental indenture also contains restrictions on the disposal of the common stock of these subsidiaries. These covenants are subject to important qualifications and limitations.
Use of Proceeds	We intend to use the net proceeds for general corporate purposes. See “Use of Proceeds” on page S-8 of this prospectus supplement.
Risk Factors	You should carefully consider all information set forth and incorporated by reference in this prospectus supplement and the accompanying prospectus and, in particular, you should carefully read the section entitled “Risk Factors” on page S-4 of this prospectus supplement and the section entitled “Item 1A. Risk Factors” of our Annual Report on Form 10-K for the year ended December 31, 2020 before purchasing any of the notes.

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No Public Market The notes are a new issue of securities with no established trading market. We do not intend to apply for listing of the notes on any securities exchange or for quotation of the notes on any automated dealer quotation system. The underwriters have advised us that they intend to make a market in the notes after this offering is completed, but they are not obligated to do so and may discontinue any market-making at any time without notice to or consent of existing noteholders.

S-3

RISK FACTORS

Before you invest in the notes, you should carefully consider the risks involved. Accordingly, you should carefully consider the information contained in or incorporated by reference into this prospectus supplement and the accompanying prospectus, including the risk factors listed below, in our Annual Report on Form 10-K for the year ended December 31, 2020, and in the other documents incorporated by reference in this prospectus supplement.

Our substantial indebtedness could adversely affect our financial health and prevent us from fulfilling our obligations under the notes.

We have now and, after this offering, will continue to have a significant amount of indebtedness. As of June 30, 2021, we had total indebtedness of approximately $2.9 billion, including our subordinated debentures.

We may incur additional indebtedness that may adversely affect our ability to meet our financial obligations under the notes.

The terms of the notes do not impose any limitation on our or our subsidiaries’ ability to incur additional debt. We may incur additional indebtedness in the future, which could have important consequences to holders of the notes, including the following:

• we could have insufficient cash to meet our financial obligations, including our obligations under the notes;

• our ability to obtain additional financing for working capital, capital expenditures or general corporate purposes may be impaired; and

• a significant degree of debt could make us more vulnerable to changes in general economic conditions and also could affect the financial strength ratings of our insurance subsidiaries.

We are an insurance holding company and, therefore, may not be able to receive dividends in amounts needed to service our debt.

As an insurance holding company, our principal assets are the shares of capital stock of our insurance company subsidiaries. We have to rely on dividends from our insurance company subsidiaries to meet our obligations for paying principal and interest on outstanding debt obligations and for paying corporate expenses. The payment of dividends by our insurance company subsidiaries is subject to regulatory restrictions and will depend on the surplus and future earnings of these subsidiaries, as well as the regulatory restrictions. As a result, we may not be able to receive dividends from these subsidiaries at times and in amounts necessary to meet our obligations under the notes.

The notes will be effectively subordinated to the liabilities of our subsidiaries.

We have limited operations of our own and derive substantially all of our revenue and cash flow from our subsidiaries. None of our subsidiaries will guarantee the notes. Creditors of our subsidiaries (including policyholders and trade creditors) will generally be entitled to payment from the assets of those subsidiaries before those assets can be distributed to us. As a result, the notes will effectively be subordinated to the prior payment of all of the debts (including amounts owed to policyholders and trade payables) of our subsidiaries. As of June 30, 2021, our subsidiaries had approximately $5.9 million in outstanding debt and our insurance subsidiaries had gross reserves for losses and loss expenses of approximately $14.5 billion.

If an active trading market does not develop for the notes, you may not be able to resell them.

Prior to this offering, there was no public market for the notes. We do not intend to apply for a listing of the notes on any national securities exchange. The underwriters have advised us that they intend to make a market in

S-4

the notes after this offering is completed, but they are not obligated to do so and may discontinue any market- making at any time without notice to or consent of existing noteholders. We cannot assure you that an active trading market will develop, or if developed, continue, for the notes. If no active trading market develops or continues, you may not be able to resell your notes at their fair market value or at all. Future trading prices of the notes will depend on many factors, including, among other things, prevailing interest rates, our operating results and the market for similar securities.

Changes in our credit ratings or the debt markets could adversely affect the market price of the notes.

The market price for the notes depends on many factors, including, among other things:

• our credit ratings with major credit rating agencies, including with respect to the notes;

• the prevailing interest rates being paid by other companies similar to us;

• our operating results, financial condition, financial performance and future prospects; and

• economic, financial, geopolitical, regulatory and judicial events that affect us, the industries and markets in which we are doing business and the financial markets generally, including the ongoing COVID-19 pandemic and the related impact on the U.S. and global economies, continuing market volatility and uncertainty about the strength and speed of recovery in the United States and other key economies, and the ongoing extremely low interest rate environment.

The price of the notes may be adversely affected by unfavorable changes in these factors. The condition of the financial markets and prevailing interest rates have fluctuated in the past and are likely to fluctuate in the future. Such fluctuations could have an adverse effect on the price of the notes.

In addition, credit rating agencies continually review their ratings for the companies that they follow, including us. The credit rating agencies also evaluate the insurance industry as a whole and may change our credit rating based on their overall view of our industry. A negative change in our rating could have an adverse effect on the price of the notes.

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FORWARD-LOOKING STATEMENTS

This prospectus supplement and the accompanying prospectus and those documents incorporated by reference herein and therein may contain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Some of the forward-looking statements can be identified by the use of forward- looking words such as “believes,” “expects,” “potential,” “continued,” “may,” “will,” “should,” “seeks,” “approximately,” “predicts,” “intends,” “plans,” “estimates,” “anticipates” or the negative version of those words or other comparable words. Any forward-looking statements contained or incorporated by reference in this prospectus supplement and the accompanying prospectus, including statements related to our outlook for the industry and for our performance for the year 2021 and beyond, are based upon our historical performance and on current plans, estimates and expectations. The inclusion of this forward-looking information should not be regarded as a representation by us, the underwriters or any other person that the future plans, estimates or expectations contemplated by us will be achieved. They are subject to various risks and uncertainties, including but not limited to:

• the cyclical nature of the property casualty industry;

• the impact of significant competition, including new alternative entrants to the industry;

• the long-tail and potentially volatile nature of the insurance and reinsurance business;

• product demand and pricing;

• claims development and the process of estimating reserves;

• investment risks, including those of our portfolio of fixed maturity securities and investments in equity securities, including investments in financial institutions, municipal bonds, mortgage-backed securities, loans receivable, investment funds, including real estate, merger arbitrage, energy related and private equity investments;

��

• the effects of emerging claim and coverage issues;

• the uncertain nature of damage theories and loss amounts, including claims for cyber security-related risks;

• natural and man-made catastrophic losses, including as a result of terrorist activities;

• the ongoing COVID-19 pandemic;

• the impact of climate change, which may alter the frequency and increase the severity of catastrophe events;

• general economic and market activities, including inflation, interest rates and volatility in the credit and capital markets;

• the impact of conditions in the financial markets and the global economy, and the potential effect of legislative, regulatory, accounting or other initiatives taken in response to it, on our results and financial condition;

• foreign currency and political risks (including those associated with the United Kingdom’s withdrawal from the European Union, or “Brexit”) relating to our international operations;

• our ability to attract and retain key personnel and qualified employees;

• continued availability of capital and financing;

• the success of our new ventures or acquisitions and the availability of other opportunities;

• the availability of reinsurance;

• our retention under the Terrorism Risk Insurance Program Reauthorization Act of 2019;

• the ability or willingness of our reinsurers to pay reinsurance recoverables owed to us;

S-6

• other legislative and regulatory developments, including those related to business practices in the insurance industry;

• credit risk relating to our policyholders, independent agents and brokers;

• changes in the ratings assigned to us or our insurance company subsidiaries by rating agencies;

• the availability of dividends from our insurance company subsidiaries;

• potential difficulties with technology and/or cyber security issues;

• the effectiveness of our controls to ensure compliance with guidelines, policies and legal and regulatory standards; and

• other risks detailed in our Annual Report on Form 10-K for the year ended December 31, 2020, and from time to time in our other filings with the SEC.

We describe some of these risks and uncertainties in greater detail under the caption “Risk Factors” beginning on page S-4 of this prospectus supplement, beginning on page 4 of the accompanying prospectus and in our Annual Report on Form 10-K for the year ended December 31, 2020, which is incorporated herein by reference. These risks and uncertainties could cause our actual results for the year 2021 and beyond to differ materially from those expressed in any forward-looking statement we make. Any projections of growth in our revenues would not necessarily result in commensurate levels of earnings. Our future financial performance is dependent upon factors discussed elsewhere in this prospectus supplement and the accompanying prospectus and the documents incorporated by reference herein and therein. Forward-looking statements speak only as of the date on which they are made. Our filings with the SEC, which discuss these risks and uncertainties, are described below under the captions “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.”

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USE OF PROCEEDS

We estimate that we will receive approximately $            million in net proceeds from this offering after deducting the underwriting discounts and commissions and our estimated expenses for this offering.

We intend to use the net proceeds for general corporate purposes.

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CAPITALIZATION

The following table shows our capitalization as of June 30, 2021 and as adjusted to give effect to the principal amount of notes offered by this prospectus supplement and the accompanying prospectus. You should read this table in conjunction with our historical consolidated financial statements and the other financial and statistical information that are included or incorporated by reference in this prospectus supplement and the accompanying prospectus.

	As of June 30, 2021
	(In thousands, except percentage data)
	Actual			As Adjusted
Debt:
% Senior Notes due 2061	$	—		$
Other senior notes and other debt		1,911,753			1,911,753
Subordinated debentures		1,007,293			1,007,293
Total debt		2,919,046
Equity:
Preferred stock, par value $0.10 per share:
No shares issued		—			—
Common stock, par value $0.20 per share:
177,413,970 shares issued and outstanding, net of treasury shares		70,535			70,535
Additional paid-in capital		1,035,166			1,035,166
Retained earnings		8,682,088			8,682,088
Accumulated other comprehensive loss		(122,444	)		(122,444	)
Treasury stock, at cost, 175,262,530 shares		(3,087,069	)		(3,087,069	)
Total common stockholders’ equity		6,578,276			6,578,276
Noncontrolling interests		9,678			9,678
Total equity		6,587,954			6,587,954
Total capitalization	$	9,507,000		$
Ratios:
Total debt to total capitalization		30.7	%		%

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DESCRIPTION OF NOTES

The notes offered by this prospectus supplement and the accompanying prospectus constitute a series of debt securities, which are described more fully in the accompanying prospectus, to be issued pursuant to an indenture to be dated as of May 12, 2020, which we refer to as the senior indenture, between us and The Bank of New York Mellon, as trustee, as supplemented by a supplemental indenture setting forth the terms of the notes. We sometimes refer to the senior indenture and the related supplemental indenture, together, as the indenture. The following description of the particular terms of the notes offered hereby supplements, and to the extent inconsistent therewith replaces, the description of the general terms and provisions of the debt securities set forth in the accompanying prospectus.

The following description is a summary of selected portions of the indenture. It does not restate the indenture in its entirety. We urge you to read the indenture because it, and not this description, defines your rights as holders of these notes.

Ranking

The notes:

• are unsecured general obligations of W. R. Berkley Corporation;

• are equal in right of payment with all of our existing and future unsecured senior debt; and

• are senior in right of payment to all of our existing and future subordinated debt, including our subordinated debentures.

The notes will effectively rank junior to any of our secured indebtedness of and to all existing and future liabilities of our subsidiaries, including amounts owed to policyholders and trade payables. Since substantially all of our operations are conducted through subsidiaries, our cash flow and subsequent ability to service debt, including the notes, are dependent on the earnings of our subsidiaries and the distribution of those earnings through dividends, or upon loans or other payments of funds by the subsidiaries, to us. The subsidiaries are separate and distinct legal entities and have no obligation to pay any amount pursuant to the notes or otherwise, whether by dividends, loans or other payments. In addition, since our significant subsidiaries are insurance companies, their ability to pay dividends to us is subject to regulatory limitations. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources” in our Annual Report on Form 10-K for the year ended December 31, 2020, our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2021, and our Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2021, which are incorporated in this prospectus supplement by reference.

As of June 30, 2021, before giving effect to this offering, we had approximately $2.9 billion of indebtedness outstanding (including our subordinated debentures), none of which was secured, and our subsidiaries had $5.9 million in outstanding debt. The indenture will permit us and our subsidiaries to incur additional debt.

Principal, Maturity and Interest

The notes are initially being offered in the aggregate principal amount of $                million. We will issue the notes in denominations of $2,000 and integral multiples of $1,000. The notes will mature on September    , 2061. We may, without the consent of the holders, increase the aggregate principal amount of this series of notes and issue additional notes (“additional notes”) in the future, on the same terms and conditions and with the same CUSIP number as the notes being offered hereby and such additional notes will form a single series with the notes offered hereby; provided that such additional notes shall be fungible for U.S. federal income tax purposes with the previously issued notes.

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Interest on the notes will accrue at the rate of            % per year. Interest will be payable semi-annually in arrears on March 30 and September 30, beginning on March 30, 2022 to the holders in whose names such notes are registered at the close of business on the immediately preceding March 15 and September 15 (whether or not a business day).

Interest on the notes will accrue from             , 2021 or, if interest has already been paid or provided for, from the date it was most recently paid or provided for. Interest will be computed on the basis of a 360-day year comprised of twelve 30-day months.

The notes will not be entitled to the benefit of any sinking fund.

Optional Redemption

Prior to March    , 2061 (the date that is six months prior to the maturity date of the notes) the notes may be redeemed, in whole or in part, at our option, at any time or from time to time, on notice given not more than 60 days, nor less than 10 days, prior to the date of redemption, at a redemption price equal to the greater of:

• 100% of the principal amount of the notes being redeemed; and

• the sum of the present values of the remaining scheduled payments of principal and interest thereon that would be due if the notes matured on March    , 2061 (not including any portion of such payments of interest accrued as of the date of such redemption, which we refer to as the “Redemption Date”) discounted to the Redemption Date on a semiannual basis (assuming a 360-day year consisting of twelve 30-day months) at the Adjusted Treasury Rate, plus            basis points, as calculated by an Independent Investment Banker;

in each case plus accrued and unpaid interest thereon to, but not including, the Redemption Date.

On or after March    , 2061 (the date that is six months prior to the maturity date of the notes), the notes may be redeemed, in whole or in part, at our option, at any time or from time to time, on notice given not more than 60 days, nor less than 10 days, prior to the date of redemption, at a redemption price equal to 100% of the principal amount of any notes to be redeemed plus accrued and unpaid interest thereon to, but not including, the Redemption Date.

“Adjusted Treasury Rate” means, with respect to any Redemption Date:

• the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently published statistical release designated “H.15” published by the Board of Governors of the Federal Reserve System (or any successor publication which is published weekly by the Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities adjusted to constant maturity) under the caption “Treasury Constant Maturities,” for the maturity corresponding to the Comparable Treasury Issue (if no maturity is within three months before or after the Remaining Life (as defined below), yields for the two published maturities most closely corresponding to the Comparable Treasury Issue shall be determined and the Adjusted Treasury Rate shall be interpolated or extrapolated from such yields on a straight line basis, rounding to the nearest month); or

• if such release (or any successor release) is not published during the week preceding the calculation date or does not contain such yields, the rate per annum equal to the semi-annual equivalent yield to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such Redemption Date.

The Adjusted Treasury Rate shall be calculated on the third business day preceding the Redemption Date.

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“Comparable Treasury Issue” means, with respect to any Redemption Date, the United States Treasury security selected by an Independent Investment Banker as having a maturity comparable to the remaining term of the notes to be redeemed that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of those notes (“Remaining Life”).

“Comparable Treasury Price” means, with respect to any Redemption Date, (1) the average of three Reference Treasury Dealer Quotations for such Redemption Date, after excluding the highest and lowest Reference Treasury Dealer Quotations, or (2) if the Independent Investment Banker obtains fewer than three such Reference Treasury Dealer Quotations, the average of all such quotations.

“Independent Investment Banker” means, with respect to any Redemption Date, one of the Reference Treasury Dealers appointed by us.

“Reference Treasury Dealer” means, with respect to any Redemption Date:

• each of BofA Securities, Inc., Credit Suisse Securities (USA) LLC, J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC (or any affiliate of any of the foregoing that is a Primary Treasury Dealer (as defined below)), and their respective successors; provided that if any of the foregoing ceases to be a primary U.S. Government securities dealer in the United States (a “Primary Treasury Dealer”), we will substitute another Primary Treasury Dealer; and

• any other Primary Treasury Dealer selected by us.

“Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Independent Investment Banker, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Independent Investment Banker at 5:00 p.m., New York City time, on the third business day preceding such Redemption Date.

We will mail a notice of redemption at least 30 days but not more than 60 days before the Redemption Date to each holder of notes to be redeemed. If we elect to redeem fewer than all of the notes, the trustee will select in a fair and appropriate manner, including pro rata or by lot, the notes to be redeemed in whole or in part; provided, that if the notes are represented by global notes, beneficial interests in the notes will be selected for redemption by DTC in accordance with its standard procedures therefor.

Unless we default in payment of the redemption price, on and after the Redemption Date, interest will cease to accrue on the notes or portions thereof called for redemption.

Additional Covenants of W. R. Berkley

We refer you to the section entitled “Description of the Debt Securities” in the accompanying prospectus for a description of certain covenants applicable to the notes. In addition to the foregoing, the following covenants will apply to the notes for the benefit of the holders of the notes:

Limitation on Liens

Because we are a holding company, our assets consist primarily of the securities of our subsidiaries. The negative pledge provisions of the supplemental indenture limit our ability to pledge some of these securities. The supplemental indenture provides that, except for liens specifically permitted by the supplemental indenture, we will not, and will not permit any subsidiary to, create, assume, incur or permit to exist any indebtedness for

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borrowed money (including any guarantee of indebtedness for borrowed money) that is secured by a pledge, lien or other encumbrance on:

• the voting securities of any “significant subsidiary,” or any subsidiary succeeding to any substantial part of the business now conducted by any significant subsidiary, which we refer to collectively as the “principal subsidiaries;” or

• the voting securities of a subsidiary that owns, directly or indirectly, the voting securities of any of the principal subsidiaries,

without providing that the notes issued and outstanding under the supplemental indenture will be secured equally and ratably with indebtedness so secured so long as such other indebtedness shall be secured.

Under the senior indenture, “subsidiary” means any corporation, partnership or other entity of which at the time of determination we or one or more other subsidiaries own directly or indirectly more than 50% of the outstanding shares of the capital voting stock (or other interests) entitled to vote in the election of directors, managers or trustees thereof. Under the supplemental indenture, “significant subsidiary” means a subsidiary which meets any of the following conditions:

• our and our other subsidiaries’ investments in and advances to the subsidiary exceed ten percent of our total assets as of the end of our most recently completed fiscal year;

• our and our other subsidiaries’ proportionate share of the subsidiary’s total assets exceed ten percent of our total assets as of the end of our most recently completed fiscal year; or

• our and our other subsidiaries’ equity in the subsidiary’s income from continuing operations before income taxes, extraordinary items and cumulative effect of a change in accounting principles exceeds ten percent of our income from continuing operations before income taxes, extraordinary items and cumulative effect of a change in accounting principles for our most recently completed fiscal year.

As of the date of this prospectus supplement, our only significant subsidiary is Berkley Insurance Company.

Restrictions on Certain Dispositions

The supplemental indenture also provides that we will not, and will not permit any of our subsidiaries to, issue, sell, assign, transfer or otherwise dispose of, directly or indirectly, any of the common stock of our principal subsidiaries (except to us or to one or more of our other subsidiaries or for the purpose of qualifying directors), unless:

• the issuance, sale, assignment, transfer or other disposition is required to comply with the order of a court or regulatory authority of competent jurisdiction, other than an order issued at our request or at the request of one of our subsidiaries;

• the entire common stock that we or our subsidiaries own is disposed of in a single transaction or in a series of related transactions for consideration consisting of cash or other property that is at least equal to the fair value of such common stock; or

• after giving effect to the issuance, sale, assignment, transfer or other disposition, we and our subsidiaries would own directly or indirectly at least 80% of the issued and outstanding common stock of such principal subsidiary and such issuance, sale, assignment, transfer or other disposition is made for consideration consisting of cash or other property which is at least equal to the fair value of such common stock.

The term “fair value,” when used with respect to common stock, means the fair value thereof as determined in good faith by our board of directors.

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Defeasance

The provisions of the senior indenture relating to defeasance, which are described under the caption “Description of the Debt Securities—Discharge, Defeasance and Covenant Defeasance” in the accompanying prospectus, will apply to the notes.

Book-Entry System, Form and Delivery

The notes initially will be issued in book-entry form and represented by one or more global notes. The global notes will be deposited with, or on behalf of, DTC, New York, New York, as depositary, and registered in the name of Cede & Co., the nominee of DTC. Beneficial interests in a global note will be represented through book-entry accounts of financial institutions acting on behalf of the beneficial owners as direct and indirect participants in DTC. Investors may elect to hold interests in a global note through either DTC (in the United States) or Clearstream Banking, S.A. (“Clearstream”), or Euroclear Bank S.A./N.V. (the “Euroclear Operator”), as operator of the Euroclear System (“Euroclear”) (in Europe), either directly if they are participants in such systems or indirectly through organizations that are participants in such systems. Clearstream and Euroclear will hold interests on behalf of their participants through customers’ securities accounts in Clearstream’s and Euroclear’s names on the books of their U.S. depositaries, which in turn will hold such interests in customers’ securities accounts in the U.S. depositaries’ names on the books of DTC. Citibank, N.A. will act as the U.S. depositary for Clearstream, and JPMorgan Chase Bank, N.A. will act as the U.S. depositary for Euroclear.

Unless and until it is exchanged for individual certificates evidencing notes under the limited circumstances described below, a global note may not be transferred except as a whole by the depositary to its nominee or by the nominee to the depositary, or by the depositary or its nominee to a successor depositary or to a nominee of the successor depositary.

DTC has advised us that it is:

• a limited-purpose trust company organized under the New York Banking Law;

• a “banking organization” within the meaning of the New York Banking Law;

• a member of the Federal Reserve System;

• a “clearing corporation” within the meaning of the New York Uniform Commercial Code; and

• a “clearing agency” registered pursuant to the provisions of Section 17A of the Securities Exchange Act of 1934 (the “Exchange Act”).

Clearstream has advised us that it is incorporated under the laws of Luxembourg as a professional depositary. Clearstream holds securities for its customers and facilitates the clearance and settlement of securities transactions between its customers through electronic book-entry changes in accounts of its customers, thereby eliminating the need for physical movement of certificates. Clearstream provides to its customers, among other things, services for safekeeping, administration, clearance and settlement of internationally traded securities and securities lending and borrowing. Clearstream interfaces with domestic markets in several countries. As a professional depositary, Clearstream is subject to regulation by the Luxembourg Monetary Institute. Clearstream customers are recognized financial institutions around the world, including underwriters, securities brokers and dealers, banks, trust companies, clearing corporations and other organizations and may include the underwriters for this offering. Indirect access to Clearstream is also available to others, such as banks, brokers, dealers and trust companies that clear through or maintain a custodial relationship with a Clearstream customer either directly or indirectly.

Euroclear has advised us that it was created in 1968 to hold securities for participants of Euroclear and to clear and settle transactions between Euroclear participants through simultaneous electronic book-entry delivery against payment, thereby eliminating the need for physical movement of certificates and any risk from lack of

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simultaneous transfers of securities and cash. Euroclear provides various other services, including securities lending and borrowing, and interfaces with domestic markets in several countries. Euroclear is operated by the Euroclear Operator under contract with Euroclear Clearance System Public Limited Company (the “Cooperative”). All operations are conducted by the Euroclear Operator, and all Euroclear securities clearance accounts and Euroclear cash accounts are accounts with the Euroclear Operator, not the Cooperative. The Cooperative establishes policy for Euroclear on behalf of Euroclear participants. Euroclear participants include banks (including central banks), securities brokers and dealers and other professional financial intermediaries and may include the underwriters for this offering. Indirect access to Euroclear is also available to other firms that clear through or maintain a custodial relationship with a Euroclear participant, either directly or indirectly.

The Euroclear Operator has advised us that it is licensed by the Belgian Banking and Finance Commission to carry out banking activities on a global basis. As a Belgian bank, it is regulated and examined by the Belgian Banking Commission.

DTC holds securities that its participants deposit with DTC. DTC also facilitates the settlement among its participants of securities transactions, including transfers and pledges, in deposited securities through electronic computerized book-entry changes in participants’ accounts, which eliminates the need for physical movement of securities certificates. “Direct participants” in DTC include securities brokers and dealers, including underwriters, banks, trust companies, clearing corporations and other organizations. DTC is owned by a number of its direct participants and by the New York Stock Exchange, Inc., the NYSE American LLC and the Financial Industry Regulatory Authority, Inc. Access to the DTC system is also available to others, which we sometimes refer to as “indirect participants,” that clear transactions through or maintain a custodial relationship with a direct participant either directly or indirectly. The rules applicable to DTC and its participants are on file with the SEC.

Purchases of notes within the DTC system must be made by or through direct participants, which will receive a credit for those notes on DTC’s records. The ownership interest of the actual purchaser of notes, which we sometimes refer to as a “beneficial owner,” is in turn recorded on the direct and indirect participants’ records. Beneficial owners of notes will not receive written confirmation from DTC of their purchases. However, beneficial owners are expected to receive written confirmations providing details of their transactions, as well as periodic statements of their holdings, from the direct or indirect participants through which they purchased notes. Transfers of ownership interests in global notes are to be accomplished by entries made on the books of participants acting on behalf of beneficial owners. Beneficial owners will not receive certificates representing their ownership interests in the global notes except under the limited circumstances described below.

To facilitate subsequent transfers, all global notes deposited with DTC will be registered in the name of DTC’s nominee, Cede & Co. The deposit of notes with DTC and their registration in the name of Cede & Co. will not change the beneficial ownership of the notes. DTC has no knowledge of the actual beneficial owners of the notes. DTC’s records reflect only the identity of the direct participants to whose accounts the notes are credited, which may or may not be the beneficial owners. The participants are responsible for keeping account of their holdings on behalf of their customers.

Conveyance of notices and other communications by DTC to direct participants, by direct participants to indirect participants and by direct participants and indirect participants to beneficial owners will be governed by arrangements among them, subject to any legal requirements in effect from time to time.

Redemption notices will be sent to DTC or its nominee. If the notes are not held in definitive form, and if less than all of the notes are being redeemed, the amount of the interest of each direct participant in the notes to be redeemed will be determined in accordance with DTC’s procedures.

In any case where a vote may be required with respect to the notes, neither DTC nor Cede & Co. will give consents for or vote the global notes. Under its usual procedures, DTC will mail an omnibus proxy to us as soon

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as possible after the record date. The omnibus proxy assigns the consenting or voting rights of Cede & Co. to those direct participants to whose accounts the notes are credited on the record date identified in a listing attached to the omnibus proxy.

Principal and interest payments on the notes will be made to Cede & Co., as nominee of DTC.

DTC’s practice is to credit direct participants’ accounts on the relevant payment date unless DTC has reason to believe that it will not receive payment on the payment date. Payments by direct and indirect participants to beneficial owners will be governed by standing instructions and customary practices, as is the case with securities held for the account of customers in bearer form or registered in “street name.” Those payments will be the responsibility of participants and not of DTC or us, subject to any legal requirements in effect from time to time. Payment of principal and interest to Cede & Co. is our responsibility, disbursement of payments to direct participants is the responsibility of DTC, and disbursement of payments to the beneficial owners is the responsibility of direct and indirect participants.

Except under the limited circumstances described below, purchasers of notes will not be entitled to have notes registered in their names and will not receive physical delivery of notes. Accordingly, each beneficial owner must rely on the procedures of DTC and its participants to exercise any rights under the notes and the indenture.

The laws of some jurisdictions may require that some purchasers of securities take physical delivery of securities in definitive form. Those laws may impair the ability to transfer or pledge beneficial interests in notes.

Distributions on the notes held beneficially through Clearstream will be credited to cash accounts of its customers in accordance with its rules and procedures, to the extent received by the U.S. depositary for Clearstream. Securities clearance accounts and cash accounts with the Euroclear Operator are governed by the Terms and Conditions Governing Use of Euroclear and the related Operating Procedures of the Euroclear System, and applicable Belgian law (collectively, the “Euroclear Terms and Conditions”). The Euroclear Terms and Conditions govern transfers of securities and cash within Euroclear, withdrawals of securities and cash from Euroclear, and receipts of payments with respect to securities in Euroclear. All securities in Euroclear are held on a fungible basis without attribution of specific certificates to specific securities clearance accounts. The Euroclear Operator acts under the Euroclear Terms and Conditions only on behalf of Euroclear participants and has no record of or relationship with persons holding through Euroclear participants.

Distributions on the notes held beneficially through Euroclear will be credited to the cash accounts of its participants in accordance with the Euroclear Terms and Conditions, to the extent received by the U.S. depositary for Euroclear.

Initial settlement for the notes will be made in immediately available funds. Secondary market trading between DTC participants will occur in the ordinary way in accordance with DTC rules and will be settled in immediately available funds. Secondary market trading between Clearstream customers and/or Euroclear participants will occur in the ordinary way in accordance with the applicable rules and operating procedures of Clearstream and Euroclear and will be settled using the procedures applicable to conventional eurobonds in immediately available funds. No assurances can be given as to the effect, if any, of settlement in immediately available funds on trading activity in the notes.

Cross-market transfers between persons holding directly or indirectly through DTC, on the one hand, and directly or indirectly through Clearstream customers or Euroclear participants, on the other, will be effected in DTC in accordance with DTC rules on behalf of the relevant European international clearing system by the U.S. depositary; however, such cross-market transactions will require delivery of instructions to the relevant European international clearing system by the counterparty in such system in accordance with its rules and procedures and within its established deadlines (European time). The relevant European international clearing system will, if the transaction meets its settlement requirements, deliver instructions to the U.S. depositary to take action to effect

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final settlement on its behalf by delivering or receiving the notes in DTC, and making or receiving payment in accordance with normal procedures for same-day funds settlement applicable to DTC. Clearstream customers and Euroclear participants may not deliver instructions directly to their U.S. depositaries.

Because of time-zone differences, credits of the notes received in Clearstream or Euroclear as a result of a transaction with a DTC participant will be made during subsequent securities settlement processing and will be credited the business day following the DTC settlement date. Such credits or any transactions in the notes settled during such processing will be reported to the relevant Clearstream customers or Euroclear participants on such business day. Cash received in Clearstream or Euroclear as a result of sales of the notes by or through a Clearstream customer or a Euroclear participant to a DTC participant will be received with value on the DTC settlement date but will be available in the relevant Clearstream or Euroclear cash account only as of the business day following settlement in DTC.

DTC, Clearstream and Euroclear are under no obligation to provide their services as depositaries for the notes and may discontinue providing their services at any time. We, the trustee and the underwriters will not have any responsibility for the performance by DTC, Clearstream, Euroclear or their direct or indirect participants under the rules and procedures governing these organizations.

As noted above, beneficial owners of notes generally will not receive certificates representing their ownership interests in the notes. However, if:

• DTC notifies us that it is unwilling or unable to continue as a depositary for the global notes or if DTC ceases to be a clearing agency registered under the Exchange Act at a time when it is required to be registered and a successor depositary is not appointed within 90 days of the notification to us or of our becoming aware of DTC’s ceasing to be so registered, as the case may be;

• we determine, in our sole discretion, not to have the notes represented by one or more global notes; or

• an event of default under the indenture has occurred and is continuing with respect to the notes,

we will prepare and deliver certificates for the notes in exchange for beneficial interests in the global notes. Any beneficial interest in a global note that is exchangeable under the circumstances described in the preceding sentence will be exchangeable for notes in definitive certificated form registered in the names that the depositary directs. It is expected that these directions will be based upon directions received by the depositary from its participants with respect to ownership of beneficial interests in the global notes.

We have provided the descriptions of the operations of DTC, Clearstream and Euroclear in this prospectus supplement solely as a matter of convenience. We take no responsibility for the accuracy of this information. These operations and procedures are solely within the control of those organizations and are subject to change by them from time to time.

About the Trustee

The Bank of New York Mellon is the trustee. Subject to the provisions of the Trust Indenture Act of 1939, as amended, the trustee is under no obligation to exercise any of its powers vested in it by the indenture at the request of any holder of the notes unless the holder offers the trustee reasonable indemnity satisfactory to it against the costs, expenses and liabilities which might result. The trustee is not required to expend or risk its own funds or otherwise incur any financial liability in performing its duties if the trustee reasonably believes that it is not reasonably assured of repayment or adequate indemnity. We have entered, and from time to time may continue to enter, into banking or other relationships with The Bank of New York Mellon or its affiliates.

The trustee may resign or be removed with respect to one or more series of debt securities under the indenture, and a successor trustee may be appointed to act with respect to such series.

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MATERIAL UNITED STATES FEDERAL INCOME TAX CONSIDERATIONS

The following is a general discussion of the material U.S. federal income tax considerations relating to the purchase, ownership and disposition of the notes. It is based upon the provisions of the U.S. Internal Revenue Code of 1986, as amended (the “Code”), Treasury Regulations promulgated thereunder and administrative and judicial interpretations thereof, all as in effect on the date hereof, and all of which are subject to change, possibly with retroactive effect, or to different interpretations. This discussion applies only to notes that are held as “capital assets,” within the meaning of the Code, by a holder (as defined below) who purchases notes in the initial offering at their “issue price” (i.e., the first price at which a substantial amount of the notes is sold to the public).

This discussion is for general information only and does not address all of the material tax considerations that may be relevant to a holder in light of its particular circumstances or to holders subject to special treatment under U.S. federal income tax laws (such as banks, insurance companies, tax-exempt entities, retirement plans, dealers in securities, real estate investment trusts, regulated investment companies, partnerships or other entities classified as partnerships for U.S. federal income tax purposes, persons holding the notes as part of a “straddle,” “hedge,” “conversion” or other integrated transaction, United States holders (as defined below) whose functional currency is not the U.S. dollar, former citizens or residents of the United States, holders who mark securities to market for U.S. federal income tax purposes, or taxpayers that purchase or sell notes as part of a wash sale for tax purposes). This discussion does not address any state, local or foreign tax consequences, any U.S. federal estate, gift or alternative minimum tax consequences, the consequences of the Medicare Contribution Tax on investment income, or the requirements under Section 451(b) of the Code for certain holders to conform the timing of income accruals with respect to the notes to their financial statements.

For purposes of this discussion, a “United States holder” is a beneficial owner of a note that is, for U.S. federal income tax purposes:

• an individual who is a citizen or resident of the United States;

• a corporation, or other entity treated as a corporation for U.S. federal income tax purposes, created or organized in or under the laws of the United States, any state thereof or the District of Columbia;

• an estate, the income of which is subject to U.S. federal income tax regardless of sources; or

• a trust, if (a) a court within the United States is able to exercise primary supervision over administration of the trust and one or more United States persons have authority to control all substantial decisions of the trust or (b) it has a valid election in effect under the applicable Treasury Regulation to be treated as a domestic trust.

For purposes of this discussion, a “non-United States holder” is a beneficial owner of a note that is not a “United States holder,” and “holders” refers to United States holders and non-United States holders. Neither the term “non-United States holder” nor the term “United States holder” includes a partnership for U.S. federal income tax purposes. If any entity treated as a partnership for U.S. federal income tax purposes holds the notes, the tax treatment of a partner in the partnership will generally depend upon the status and activities of the partnership and the partner. Prospective holders that are entities treated as partnerships for U.S. federal income tax purposes should consult their own tax advisors regarding the U.S. federal income tax consequences to them and their partners of holding the notes.

Persons considering the purchase of the notes should consult their own tax advisors with respect to the U.S. federal income tax considerations relating to the purchase, ownership and disposition of the notes in light of their own particular circumstances, as well as the effect of any state, local, foreign and other tax laws.

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United States Holders

Interest Income

A United States holder must generally include stated interest on a note as ordinary income at the time such interest is received or accrued, in accordance with such United States holder’s method of accounting for U.S. federal income tax purposes.

Sale, Exchange, Redemption or Other Disposition of Notes

Upon the sale, exchange, redemption or other disposition of a note, a United States holder will generally recognize gain or loss equal to the difference between the amount realized (less any accrued interest not previously included in the United States holder’s income, which will be taxable as ordinary income) on the sale, exchange, redemption or other disposition and such United States holder’s adjusted tax basis in the note. A United States holder’s adjusted tax basis in a note generally will be its initial purchase price. Gain or loss recognized on a disposition of a note generally will be capital gain or loss and generally will be long-term capital gain or loss if the note has been held for more than one year. A United States holder that is an individual is generally entitled to preferential treatment for net long-term capital gains. The ability of a United States holder to deduct capital losses is limited.

Non-United States Holders

Subject to the discussion below concerning backup withholding and FATCA (as defined below), the following is a discussion of U.S. federal income tax and withholding tax considerations generally applicable to non-United States holders:

(a) payments of principal and interest with respect to a note held by or for a non-United States holder will not be subject to U.S. federal income or withholding tax, provided that, in the case of amounts treated as interest, (i) such non-United States holder does not own, actually or constructively, 10% or more of the total combined voting power of all classes of our stock entitled to vote, (ii) such non-United States holder is not a controlled foreign corporation, within the meaning of Section 957(a) of the Code, that is related, directly or indirectly, to us through stock ownership, (iii) such non-United States holder is not a bank receiving interest on a loan entered into in the ordinary course of its trade or business, (iv) such interest is not effectively connected with the conduct by the non-United States holder of a trade or business within the United States, and (v) such non-United States holder complies with applicable certification requirements related to its non-U.S. status including, in general, furnishing an IRS Form W-8BEN, Form W-8BEN-E, or other applicable Form W-8; and

(b) a non-United States holder will generally not be subject to U.S. federal income or withholding tax on amounts treated as gain realized on the sale, exchange, redemption or other disposition of a note, provided that (i) (A) such gain is not effectively connected with the conduct by such non-United States holder of a trade or business within the United States (and, if required by an applicable tax treaty, is not attributable to a permanent establishment in the United States), and (B) such non-United States holder is not an individual who has been present in the United States for 183 days or more in the taxable year of disposition and certain other requirements are met, and (ii) the gain does not represent accrued interest, in which case the rules for interest would generally apply.

A non-United States holder that does not qualify for an exemption from U.S. federal income and withholding tax under the preceding paragraph generally will be subject to withholding of U.S. federal income tax at a 30% rate (or lower applicable treaty rate provided that we, or our paying agent, receive appropriate documentation (generally an IRS Form W-8BEN or W-8BEN-E) certifying that such holder is eligible for treaty benefits) on payments of interest on the notes.

However, if interest on the notes is effectively connected with the conduct by a non-United States holder of a trade or business within the United States, such interest will be subject to U.S. federal income tax on a net

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income basis at the rate applicable to U.S. persons generally (and, with respect to corporate holders, may also be subject to a 30% branch profits tax). If interest is subject to U.S. federal income tax on a net income basis in accordance with these rules, such payments will not be subject to U.S. withholding tax so long as the non-United States holder provides us or our paying agent with the appropriate documentation (generally an IRS Form W-8ECI).

Additional Withholding Requirements

Pursuant to Sections 1471 through 1474 of the Code and the Treasury Regulations promulgated thereunder (“FATCA”), we may be required to withhold U.S. tax at the rate of 30% on payments of interest made to non-U.S. financial institutions and certain other non-U.S. non-financial entities that fail to comply with certain information reporting obligations. Non-United States holders should consult with their own tax advisors regarding the possible implications of FATCA on their investment in the notes.

Current provisions of the Code and the Treasury Regulations that govern FATCA treat gross proceeds from the sale or other disposition of debt obligations that can produce U.S.-source interest (such as the notes) as subject to FATCA withholding after December 31, 2018. However, under proposed Treasury Regulations (the preamble to which specifies that taxpayers are permitted to rely on them pending finalization), such gross proceeds are not subject to FATCA withholding.

Backup Withholding and Information Reporting

Backup withholding and information reporting requirements generally apply to interest and principal payments made to, and to the proceeds of sales by, certain non-corporate United States holders. A United States holder not otherwise exempt from backup withholding generally can avoid backup withholding by providing IRS Form W-9. In the case of a non-United States holder, backup withholding and information reporting will not apply to payments on, or proceeds from the sale, exchange, redemption or other disposition of, a note if the statement referred to in clause (a)(v) of the paragraph under the heading “—Non-United States Holders” has been received. Withholding agents must nevertheless report to the IRS and to each non-United States holder the amount of interest paid with respect to the notes held by such non-United States holder and the rate of withholding (if any) applicable to such non-United States holder. Any amounts withheld under the backup withholding rules generally will be allowed as a refund or a credit against the holder’s U.S. federal income tax liability, provided the required information is timely furnished to the IRS.

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CERTAIN ERISA CONSIDERATIONS

A fiduciary of a pension, profit-sharing or other employee benefit plan (a “plan”) subject to the U.S. Employee Retirement Income Security Act of 1974, as amended (“ERISA”), should consider the fiduciary standards of ERISA in the context of the plan’s particular circumstances before authorizing an investment in the notes. Accordingly, among other factors, the fiduciary should consider whether the investment would satisfy the prudence and diversification requirements of ERISA and would be consistent with the documents and instruments governing the plan, and whether the investment would involve a prohibited transaction under Section 406 of ERISA or Section 4975 of the Code.

Section 406 of ERISA and Section 4975 of the Code prohibit plans, as well as individual retirement accounts and Keogh plans subject to Section 4975 of the Code (also “plans”), from engaging in certain transactions involving “plan assets” with persons who are “parties in interest” under ERISA or “disqualified persons” under the Code (“parties in interest”) with respect to the plan. A violation of these prohibited transaction rules may result in civil penalties or other liabilities under ERISA and/or an excise tax under Section 4975 of the Code for those persons, unless exemptive relief is available under an applicable statutory, regulatory or administrative exemption. Certain employee benefit plans and arrangements including those that are governmental plans (as defined in Section 3(32) of ERISA), certain church plans (as defined in Section 3(33) of ERISA) and foreign plans (as described in Section 4(b)(4) of ERISA) (“non-ERISA arrangements”) are not subject to the requirements of ERISA or Section 4975 of the Code but may be subject to similar provisions under applicable federal, state, local, foreign or other regulations, rules or laws (“similar laws”).

The acquisition of the notes by a plan with respect to which we or certain of our affiliates are or become a party in interest may constitute or result in a prohibited transaction under ERISA or Section 4975 of the Code, unless those notes are acquired pursuant to and in accordance with an applicable exemption. Section 408(b)(17) of ERISA and Section 4975(d)(20) of the Code provide an exemption for the purchase and sale of securities where neither we nor any of our affiliates have or exercise any discretionary authority or control or render any investment advice with respect to the assets of the plan involved in the transaction and the plan pays no more and receives no less than “adequate consideration” in connection with the transaction (the “service provider exemption”). The U.S. Department of Labor has also issued five prohibited transaction class exemptions, or “PTCEs,” that may provide exemptive relief if required for direct or indirect prohibited transactions that may arise from the purchase or holding of the notes. These exemptions are:

• PTCE 84-14, an exemption for certain transactions determined or effected by independent qualified professional asset managers;

• PTCE 90-1, an exemption for certain transactions involving insurance company pooled separate accounts;

• PTCE 91-38, an exemption for certain transactions involving bank collective investment funds;

• PTCE 95-60, an exemption for transactions involving certain insurance company general accounts; and

• PTCE 96-23, an exemption for plan asset transactions managed by in-house asset managers.

Any purchaser or holder of notes or any interest therein will be deemed to have represented by its purchase and holding of the notes that it either (1) is not a plan and is not purchasing those notes on behalf of or with “plan assets” of any plan or (2) with respect to the purchase or holding is eligible for the exemptive relief available under any of the PTCEs listed above, the service provider exemption or another applicable exemption. In addition, any purchaser or holder of notes or any interest therein which is a non-ERISA arrangement will be deemed to have represented by its purchase or holding of the notes that its purchase and holding will not constitute or result in a non-exempt violation of the provisions of any similar law.

Neither we, nor any underwriter, nor any of our respective affiliates are undertaking to provide impartial investment advice, or to give advice in a fiduciary capacity, in connection with the acquisition of notes by a plan.

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Due to the complexity of these rules and the penalties that may be imposed upon persons involved in non-exempt prohibited transactions, it is important that fiduciaries or other persons considering purchasing notes on behalf of or with “plan assets” of any plan or non-ERISA arrangement consult with their counsel regarding the availability of exemptive relief under any of the PTCEs listed above, the service provider exemption or any other applicable exemption, or the potential consequences of any purchase or holding under similar laws, as applicable.

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UNDERWRITING

Under the terms and subject to the conditions contained in an underwriting agreement, dated            , 2021, between us and BofA Securities, Inc., Credit Suisse Securities (USA) LLC, J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC, as representatives of the underwriters, the underwriters named below have severally agreed to purchase, and we have agreed to sell to them, severally, the respective principal amount of the notes set forth opposite their names below:

Underwriters	Principal Amount of Notes
BofA Securities, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .	$
Credit Suisse Securities (USA) LLC
J.P. Morgan Securities LLC
Morgan Stanley & Co. LLC
Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .	$

The underwriting agreement provides that the obligations of the several underwriters to pay for and accept delivery of the notes are subject to, among other things, the approval of certain legal matters by their counsel and certain other conditions. The underwriters are obligated to take and pay for all of the notes if any are taken.

The underwriters initially propose to offer the notes directly to the public at the public offering price set forth on the cover page of this prospectus supplement and may offer the notes to certain dealers at a price that represents a concession not in excess of            % of the principal amount of the notes. Any underwriter may allow, and any such dealers may reallow, a concession to certain other dealers not to exceed            % of the principal amount of the notes. After the initial offering of the notes, the offering price and other selling terms may from time to time be varied by the underwriters.

We have agreed to indemnify the several underwriters against certain liabilities, including liabilities under the Securities Act of 1933, as amended.

The following table shows the price to public, the underwriting discount that we are to pay to the underwriters in connection with this offering and the proceeds, before expenses, to W. R. Berkley Corporation.

	Total
Price to public (1)	$
Underwriting discount	$
Proceeds, before expenses, to W. R. Berkley Corporation	$

(1) Plus accrued interest, if any, from                , 2021 to the date of delivery.

We estimate that our total expenses relating to this offering, not including the underwriting discount, will be approximately $300,000.

We do not intend to apply for the listing of the notes on a national securities exchange, but have been advised by the underwriters that they intend to make a market in the notes. The underwriters are not obligated, however, and may discontinue market making at any time without notice. No assurance can be given as to the liquidity of the trading market for the notes.

In connection with this offering, the underwriters may purchase and sell notes in the open market. These transactions may include short sales, stabilizing transactions and purchases to cover positions created by short sales. Short sales involve the sale by the underwriters of a greater number of notes than they are required to purchase in this offering. The underwriters must close out any short position by purchasing notes in the open market. A short position is more likely to be created if the underwriters are concerned that there may be

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downward pressure on the price of the notes in the open market after pricing that could adversely affect investors who purchase in this offering. Stabilizing transactions consist of certain bids or purchases made for the purpose of preventing or retarding a decline in the market price of the notes while this offering is in progress.

The underwriters also may impose a penalty bid. This occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the representatives have repurchased notes sold by or for the account of such underwriter in stabilizing or short covering transactions.

These activities by the underwriters, as well as other purchases by the underwriters for their own accounts, may stabilize, maintain or otherwise affect the market price of the notes. As a result, the price of the notes may be higher than the price that otherwise might exist in the open market. If these activities are commenced, they may be discontinued by the underwriters at any time. These transactions may be effected in the over-the-counter market or otherwise.

Some of the underwriters and their affiliates have engaged in, and may in the future engage in, investment banking and other commercial dealings in the ordinary course of business with us or our affiliates. They have received, or may in the future receive, customary fees and commissions for these transactions. BofA Securities, Inc., Credit Suisse Securities (USA) LLC, J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC have acted as underwriters for certain of our previous public offerings of debt and equity securities.

In addition, in the ordinary course of their business activities, the underwriters and their affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. If any of the underwriters or their affiliates has a lending relationship with us, certain of those underwriters or their affiliates routinely hedge, and certain other of those underwriters or their affiliates may hedge, their credit exposure to us consistent with their customary risk management policies. Typically, such underwriters and their affiliates would hedge such exposure by entering into transactions that consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the notes offered hereby. Any such credit default swaps or short positions could adversely affect future trading prices of the notes offered hereby. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

We expect to deliver the notes against payment for the notes on or about the date specified in the last paragraph of the cover page of this prospectus supplement, which will be the fifth business day following the date of the pricing of the notes (“T+5”). Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in two business days, unless the parties to a trade expressly agree otherwise. Accordingly, purchasers who wish to trade notes on the date of pricing or the next two succeeding business days will be required, by virtue of the fact that the notes initially will settle in T+5, to specify alternative settlement arrangements to prevent a failed settlement and consult their own advisors.

Offering Restrictions

European Economic Area

Prohibition of Sales to EEA Retail Investors

Each underwriter has represented and agreed that it has not offered, sold or otherwise made available and will not offer, sell or otherwise make available any notes to any retail investor in the EEA. For the purposes of this provision:

(a) the expression “retail investor” means a person who is one (or more) of the following:

(i) a retail client as defined in point (11) of Article 4(1) of MiFID II; or

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(ii) a customer within the meaning of the Insurance Distribution Directive, where that customer would not qualify as a professional client as defined in point (10) of Article 4(1) of MiFID II; or

(iii) not a qualified investor as defined in the Prospectus Regulation; and

(b) the expression “offer” includes the communication in any form and by any means of sufficient information on the terms of the offer and the notes to be offered so as to enable an investor to decide to purchase or subscribe for the notes.

United Kingdom

Prohibition of Sales to United Kingdom Retail Investors

Each underwriter has represented and agreed that it has not offered, sold or otherwise made available and will not offer, sell or otherwise make available any notes to any retail investor in the UK.

For the purposes of this provision:

(a) the expression “retail investor” means a person who is one (or more) of the following:

(i) a retail client, as defined in point (8) of Article 2 of Regulation (EU) No 2017/565 as it forms part of domestic law in the UK by virtue of the EUWA; or

(ii) a customer within the meaning of the provisions of the FSMA and any rules or regulations made under the FSMA to implement the Insurance Distribution Directive, where that customer would not qualify as a professional client, as defined in point (8) of Article 2(1) of Regulation (EU) No 600/2014 as it forms part of domestic law in the UK by virtue of the EUWA; or

(iii) not a qualified investor as defined in Article 2 of the UK Prospectus Regulation; and

(b) the expression “offer” includes the communication in any form and by any means of sufficient information on the terms of the offer and the notes to be offered so as to enable an investor to decide to purchase or subscribe for the notes.

Other Regulatory Restrictions in the United Kingdom

Each underwriter has represented and agreed that:

(a) it has only communicated or caused to be communicated and will only communicate or cause to be communicated an invitation or inducement to engage in investment activity (within the meaning of Section 21 of the FSMA) received by it in connection with the issue or sale of the notes in circumstances in which Section 21(1) of the FSMA does not apply to W. R. Berkley Corporation; and

(b) it has complied and will comply with all applicable provisions of the FSMA with respect to anything done by it in relation to the notes in, from or otherwise involving the UK.

Switzerland

This prospectus supplement, the accompanying prospectus, any related free writing prospectus and any other document or materials relating to the issue of the notes offered hereby is not intended to constitute an offer or solicitation to purchase or invest in the notes. The notes may not be publicly offered, directly or indirectly, in Switzerland within the meaning of the Swiss Financial Services Act (“FinSA”) and no application has or will be made to admit the notes to trading on any trading venue (exchange or multilateral trading facility) in Switzerland. Neither this prospectus supplement nor any other offering or marketing material relating to the notes constitutes a prospectus pursuant to the FinSA, and neither this prospectus supplement nor any other offering or marketing material relating to the notes may be publicly distributed or otherwise made publicly available in Switzerland.

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Hong Kong

The notes have not been offered or sold and will not be offered or sold in Hong Kong by means of any document other than (i) to “professional investors” as defined in the Securities and Futures Ordinance (Cap. 571 of the Laws of Hong Kong) (the “SFO”) and any rules made thereunder, or (ii) in other circumstances which do not result in the document being a “prospectus” as defined in the Companies (Winding Up and Miscellaneous Provisions) Ordinance (Cap. 32 of the Laws of Hong Kong or which do not constitute an offer to the public within the meaning of that Ordinance; and no advertisement, invitation or document relating to the notes has been or will be issued or has been or will be in the possession of any person for the purposes of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public in Hong Kong (except if permitted to do so under the securities laws of Hong Kong) other than with respect to the notes that are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” as defined in the SFO and any rules made thereunder.

Japan

The notes have not been and will not be registered under the Financial Instruments and Exchange Law of Japan (the “Financial Instruments and Exchange Law”) and accordingly, each underwriter has acknowledged and agreed that it has not offered or sold and will not offer or sell any notes, directly or indirectly, in Japan or to, or for the account or benefit of, any resident of Japan (which term as used herein means any person resident in Japan, including any corporation or other entity organized under the laws of Japan), or to, or for the account or benefit of, others for re-offering or resale, directly or indirectly, in Japan or to, or for the account or benefit of, any resident of Japan, except pursuant to an exemption from the registration requirements of, and otherwise in compliance with, the Financial Instruments and Exchange Law and any other applicable laws, regulations or ministerial guidelines of Japan.

Singapore

This prospectus supplement has not been and will not be registered as a prospectus under the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”) by the Monetary Authority of Singapore, and the offer of the notes in Singapore is made primarily pursuant to the exemptions under Sections 274 and 275 of the SFA. Accordingly, this prospectus supplement and any other document or material in connection with the offer or sale, or invitation for subscription or purchase of the notes may not be circulated or distributed, nor may the notes be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to any person in Singapore other than (i) to an institutional investor (as defined in Section 4A of the SFA, an “Institutional Investor”), pursuant to Section 274 of the SFA, (ii) to an accredited investor (as defined in Section 4A of the SFA, an “Accredited Investor”) or other relevant person (as defined in Section 275(2) of the SFA, a “Relevant Person”) and pursuant to Section 275(1) of the SFA, or to any person pursuant to an offer referred to in Section 275(1A) of the SFA, and in accordance with the conditions specified in Section 275 of the SFA and (where applicable) Regulation 3 of the Securities and Futures (Classes of Investors) Regulations 2018, or (iii) otherwise pursuant to, and in accordance with, the conditions of any other applicable exemption or provision of the SFA.

It is a condition of the offer that where the notes are subscribed for or acquired pursuant to an offer made in reliance on Section 275 of the SFA by a Relevant Person which is:

a. a corporation (which is not an Accredited Investor), the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an Accredited Investor; or

b. a trust (where the trustee is not an Accredited Investor), the sole purpose of which is to hold investments and each beneficiary of the trust is an individual who is an Accredited Investor,

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the securities or securities-based derivatives contracts (each as defined in Section 2(1) of the SFA) of that corporation, and the beneficiaries’ rights and interest (howsoever described) in that trust, shall not be transferred within six months after that corporation or that trust has subscribed for or acquired the notes except:

i. to an Institutional Investor, an Accredited Investor, a Relevant Person, or which arises from an offer referred to in Section 275(1A) of the SFA (in the case of that corporation) or Section 276(4)(i)(B) of the SFA (in the case of that trust);

ii. where no consideration is or will be given for the transfer;

iii. where the transfer is by operation of law;

iv. as specified in Section 276(7) of the SFA; or

v. as specified in Regulation 37A of the Securities and Futures (Offers of Investments) (Securities and Securities-based Derivatives Contracts) Regulations 2018.

Singapore Securities and Futures Act Product Classification – Solely for the purposes of its obligations pursuant to Sections 309B(1)(a) and 309B(1)(c) of the SFA, W.R. Berkley has determined, and hereby notifies all relevant persons (as defined in Section 309A of the SFA) that the notes are “prescribed capital markets products” (as defined in the Securities and Futures (Capital Markets Products) Regulations 2018) and “Excluded Investment Products” (as defined in MAS Notice SFA 04-N12: Notice on the Sale of Investment Products and MAS Notice FAA-N16: Notice on Recommendations on Investment Products).

Canada

Resale Restrictions

The distribution of notes in the provinces and territories of Canada is being made on a private placement basis exempt from the requirement that we prepare and file a prospectus with the securities regulatory authorities in each province or territory where trades of these securities are made. Any resale of the notes in Canada must be made under applicable securities laws which may vary depending on the relevant jurisdiction, and which may require resales to be made under available statutory exemptions or under a discretionary exemption granted by the applicable Canadian securities regulatory authority. Purchasers are advised to seek legal advice prior to any resale of the securities.

Representations of Canadian Purchasers

By purchasing notes in Canada and accepting delivery of a purchase confirmation, a purchaser is representing to us and the dealer from whom the purchase confirmation is received that:

• the purchaser is entitled under applicable provincial securities laws to purchase the notes without the benefit of a prospectus qualified under those securities laws as it is an “accredited investor” as defined under National Instrument 45-106 – Prospectus Exemptions or Section 73.3(1) of the Securities Act (Ontario), as applicable,

• the purchaser is a “permitted client” as defined in National Instrument 31-103—Registration Requirements, Exemptions and Ongoing Registrant Obligations,

• where required by law, the purchaser is purchasing as principal and not as agent, and

• the purchaser has reviewed the text above under Resale Restrictions.

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Conflicts of Interest

Canadian purchasers are hereby notified that each of the underwriters is relying on the exemption set out in section 3A.3 or 3A.4, if applicable, of National Instrument 33-105 – Underwriting Conflicts from having to provide certain conflict of interest disclosure in this document.

Statutory Rights of Action

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement (including any amendment thereto) such as this document contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser of these securities in Canada should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

Enforcement of Legal Rights

All of our directors and officers as well as the experts named herein may be located outside of Canada and, as a result, it may not be possible for Canadian purchasers to effect service of process within Canada upon us or those persons. All or a substantial portion of our assets and the assets of those persons may be located outside of Canada and, as a result, it may not be possible to satisfy a judgment against us or those persons in Canada or to enforce a judgment obtained in Canadian courts against us or those persons outside of Canada.

Taxation and Eligibility for Investment

Canadian purchasers of notes should consult their own legal and tax advisors with respect to the tax consequences of an investment in the notes in their particular circumstances and about the eligibility of the notes for investment by the purchaser under relevant Canadian legislation.

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LEGAL MATTERS

Willkie Farr & Gallagher LLP, New York, New York, will provide us with an opinion as to legal matters in connection with the notes offered by this prospectus supplement. Sidley Austin LLP, New York, New York, will pass upon certain legal matters for the underwriters. Sidley Austin LLP has in the past represented, and is currently representing, us and our subsidiaries in various matters.

EXPERTS

The consolidated financial statements of W. R. Berkley Corporation and subsidiaries as of December 31, 2020 and 2019, and for each of the years in the three-year period ended December 31, 2020, and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2020, have been incorporated by reference herein and in the registration statement in reliance upon the reports of KPMG LLP, independent registered public accounting firm, incorporated by reference herein and upon the authority of said firm as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the informational requirements of the Exchange Act. Accordingly, we file annual, quarterly and current reports, proxy statements and other information with the SEC. You can read and copy any document that we file with the SEC at the SEC’s public reference room at 100 F Street, N.E., Washington, D.C. 20549.

Our filings with the SEC are also available from the SEC’s website at http://www.sec.gov. Please call the SEC’s toll-free telephone number at 1-800-SEC-0330 if you need further information about the operation of the SEC’s public reference rooms. Information about us is also available on our website at http://www.wrberkley.com. Such information on our website is not a part of this prospectus supplement or the accompanying prospectus.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate by reference” the information we file with it, which means that we can disclose important information to you by referring to those documents. The information incorporated by reference is an important part of this prospectus supplement. Any statement contained in a document which is incorporated by reference in this prospectus supplement is automatically updated and superseded if information contained in this prospectus supplement, or information that we later file with the SEC, modifies or replaces this information. All documents we subsequently file pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, prior to the termination of this offering, shall be deemed to be incorporated by reference into this prospectus supplement. We incorporate by reference the following documents:

• Our Annual Report on Form 10-K for the year ended December 31, 2020;

• Our Quarterly Reports on Form 10-Q for the quarterly periods ended March  31, 2021 and June 30, 2021;

• Our Definitive Proxy Statement on Schedule 14A (solely to the extent incorporated by reference into our Annual Report on Form 10-K for the year ended December 31, 2020); and

• Our Current Reports on Form 8-K filed January  29, 2021, February  3, 2021, February  4, 2021, February  10, 2021, March  12, 2021, March  16, 2021, April  19, 2021 and June 15, 2021.

To receive a free copy of any of the documents incorporated by reference in this prospectus supplement, other than any exhibits, unless the exhibits are specifically incorporated by reference into this prospectus supplement, call or write us at the following address: W. R. Berkley Corporation, Attn.: Philip S. Welt, Executive Vice President, General Counsel & Secretary, at 475 Steamboat Road, Greenwich, Connecticut 06830, phone number: (203) 629-3000.

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PROSPECTUS

W. R. Berkley Corporation

Common Stock, Preferred Stock, Depositary Shares, Debt Securities,

Warrants to Purchase Common Stock, Warrants to Purchase Preferred Stock,

Warrants to Purchase Debt Securities, Stock Purchase Contracts and Stock Purchase Units

We will provide the specific terms of these securities in supplements to this prospectus. The prospectus supplements may also add to or update the information contained in this prospectus. You should read this prospectus and any supplements carefully before you invest.

Our common stock is listed on the New York Stock Exchange under the symbol “WRB”. On November 5, 2020, the closing price of our common stock, as reported by the New York Stock Exchange, was $62.90 per share.

Investing in our securities involves risks. See “Risk Factors” on Page 4.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This prospectus may not be used to consummate sales of offered securities unless accompanied by a prospectus supplement.

You should rely only on the information contained or incorporated by reference in this prospectus or any supplement. We have not authorized anyone else to provide you with different information. We are offering these securities only in states where the offer is permitted. You should not assume that the information in this prospectus or any supplement is accurate as of any date other than the date on the front of those documents. Our business, financial condition, results of operations and prospects may have changed since that date.

The date of this prospectus is November 6, 2020.

TABLE OF CONTENTS

	Page
ABOUT THIS PROSPECTUS		1
FORWARD-LOOKING STATEMENTS		2
W. R. BERKLEY CORPORATION		4
RISK FACTORS		4
USE OF PROCEEDS		4
GENERAL DESCRIPTION OF THE OFFERED SECURITIES		5
DESCRIPTION OF OUR CAPITAL STOCK		5
DESCRIPTION OF THE DEPOSITARY SHARES		10
DESCRIPTION OF THE DEBT SECURITIES		13
DESCRIPTION OF THE WARRANTS TO PURCHASE COMMON STOCK OR PREFERRED STOCK		27
DESCRIPTION OF THE WARRANTS TO PURCHASE DEBT SECURITIES		29
DESCRIPTION OF STOCK PURCHASE CONTRACTS AND STOCK PURCHASE UNITS		30
PLAN OF DISTRIBUTION		30
LEGAL MATTERS		32
EXPERTS		32
WHERE YOU CAN FIND MORE INFORMATION		32
INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE		33

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission (the “Commission”) utilizing a “shelf” registration process, relating to the common stock, preferred stock, depositary shares, debt securities, warrants, stock purchase contracts and stock purchase units described in this prospectus. Under this shelf process, we are registering an unspecified amount of each class of the securities described in this prospectus, and we may sell any combination of the securities described in this prospectus in one or more offerings. This prospectus does not contain all of the information set forth in the registration statement as permitted by the rules and regulations of the Commission. For additional information regarding us and the offered securities, please refer to the registration statement of which this prospectus forms a part. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add to, update, supplement or clarify information contained in this prospectus. The rules of the Commission allow us to incorporate by reference information into this prospectus. This information incorporated by reference is considered to be a part of this prospectus, and information that we file later with the Commission will automatically update and supersede this information.

You should read both this prospectus and any prospectus supplement together with additional information described under the heading “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.”

Unless otherwise indicated, all references in this prospectus to “W. R. Berkley,” “we,” “us,” “our,” the “Company” or similar terms refer to W. R. Berkley Corporation together with its subsidiaries.

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FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated herein by reference may contain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Some of the forward-looking statements can be identified by the use of forward-looking words such as “believes,” “expects,” “potential,” “continued,” “may,” “will,” “should,” “seeks,” “approximately,” “predicts,” “intends,” “plans,” “estimates,” “anticipates” or the negative version of those words or other comparable words. Any forward-looking statements contained or incorporated by reference in this prospectus, including statements related to our outlook for the industry and for our performance for the year 2020 and beyond, are based upon our historical performance and on current plans, estimates and expectations. The inclusion of this forward-looking information should not be regarded as a representation by us, the underwriters or any other person that the future plans, estimates or expectations contemplated by us will be achieved. Such forward-looking statements are subject to various risks and uncertainties, including but not limited to:

• the ongoing COVID-19 pandemic, including the related impact on the U.S. and global economies;

• the cyclical nature of the property casualty industry;

• the impact of significant competition, including new alternative entrants to the industry;

• the long-tail and potentially volatile nature of the insurance and reinsurance business;

• product demand and pricing;

• claims development and the process of estimating reserves;

• investment risks, including those of our portfolio of fixed maturity securities and investments in equity securities, including investments in financial institutions, municipal bonds, mortgage-backed securities, loans receivable, investment funds, including real estate, merger arbitrage, energy-related and private equity investments;

• the effects of emerging claim and coverage issues;

• the uncertain nature of damage theories and loss amounts, including claims for cybersecurity-related risks;

• natural and man-made catastrophic losses, including as a result of terrorist activities, epidemics or pandemics, such as COVID-19;

• the impact of climate change, which may increase the frequency and severity of catastrophe events;

• general economic and market activities, including inflation, interest rates, and volatility in the credit and capital markets;

• the impact of the conditions in the financial markets and the global economy, and the potential effect of legislative, regulatory, accounting or other initiatives taken in response, on our results and financial condition;

• foreign currency and political risks (including those associated with the United Kingdom’s withdrawal from the European Union, or “Brexit”) relating to our international operations; our ability to attract and retain key personnel and qualified employees;

• continued availability of capital and financing;

• the success of our new ventures or acquisitions and the availability of other opportunities;

• the availability of reinsurance;

• our retention under the Terrorism Risk Insurance Program Reauthorization Act of 2019;

• the ability or willingness of our reinsurers to pay reinsurance recoverables owed to us;

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• other legislative and regulatory developments, including those related to business practices in the insurance industry;

• credit risk related to our policyholders, independent agents and brokers;

• changes in the ratings assigned to us or our insurance company subsidiaries by rating agencies;

• the availability of dividends from our insurance company subsidiaries;

• potential difficulties with technology and/or cybersecurity issues;

• the effectiveness of our controls to ensure compliance with guidelines, policies and legal and regulatory standards; and

• other risks detailed from time to time in our filings with the Commission.

We describe some of these risks and uncertainties in greater detail under the caption “Risk Factors” in Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2019 (our “Annual Report”), which is incorporated herein by reference. These risks and uncertainties could cause our actual results for the year 2020 and beyond to differ materially from those expressed in any forward-looking statement we make. Any projections of growth in our revenues would not necessarily result in commensurate levels of earnings. Our future financial performance is dependent upon factors discussed elsewhere in this prospectus, any related prospectus supplement and the documents incorporated by reference in this prospectus. Forward-looking statements speak only as of the date on which they are made. Except to the extent required by applicable law, we do not undertake any obligation to update or revise any forward-looking statement, whether as a result of new information, future developments or otherwise. For a discussion of factors that could cause actual results to differ, see “Risk Factors” below and the information contained in our publicly available filings with the Commission. These filings are described below under the captions “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.”

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W. R. BERKLEY CORPORATION

Overview

We are an insurance holding company that is among the largest commercial lines writers in the United States. We operate worldwide in two segments of the property and casualty business:

• Insurance – predominantly commercial insurance business, including excess and surplus lines, admitted lines and specialty personal lines throughout the United States, as well as insurance business in the United Kingdom, Continental Europe, South America, Canada, Mexico, Scandinavia, Asia and Australia; and

• Reinsurance – reinsurance business on a facultative and treaty basis, primarily in the United States, the United Kingdom, Continental Europe, Australia, the Asia-Pacific Region and South Africa, as well as operations that solely retain risk on an excess basis.

Our two reporting segments are composed of individual operating units that serve a market defined by geography, products, services or industry served. Each of our operating units is positioned close to its customer base and participates in a niche market requiring specialized knowledge. This strategy of decentralized operations allows each of our units to identify and respond quickly and effectively to changing market conditions and specific customer needs, while capitalizing on the benefits of centralized capital, investment and reinsurance management, and corporate actuarial, financial, enterprise risk management and legal staff support.

Other Information

For further information regarding us and our financial information, you should refer to our recent filings with the Commission.

We were incorporated in Delaware in 1970 as the successor to a New Jersey corporation that was incorporated in 1967. Our principal executive offices are located at 475 Steamboat Road, Greenwich, Connecticut 06830, and our telephone number is (203) 629-3000.

RISK FACTORS

Investing in our securities involves significant risks. You should carefully consider and evaluate the specific risks discussed or incorporated by reference in this prospectus and the applicable prospectus supplement, together with all other information contained or incorporated by reference in this prospectus and the applicable prospectus supplement. You should consider the risks, uncertainties and assumptions discussed under the caption “Risk Factors” in Item 1A of our Annual Report, which is incorporated by reference in this prospectus. If any of the events or circumstances described as risks actually occurs, our businesses, results of operations or financial condition could be materially and adversely affected. In such case, the market value of our securities could decline and you could lose part or all of your investment. These risk factors may be amended, supplemented or superseded from time to time by other reports we file with the Commission in the future.

USE OF PROCEEDS

Unless the applicable prospectus supplement states otherwise, we will use the net proceeds from the sale of offered securities for working capital, capital expenditures, acquisitions, stock repurchases and other general corporate purposes. Until we use the net proceeds in the manner described above, we may temporarily use them to make short-term investments or to reduce short-term borrowings.

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GENERAL DESCRIPTION OF THE OFFERED SECURITIES

We may from time to time offer under this prospectus, separately or together:

• common stock;

• preferred stock, which may be represented by depositary shares as described below;

• unsecured senior or subordinated debt securities;

• warrants to purchase common stock;

• warrants to purchase preferred stock;

• warrants to purchase debt securities;

• stock purchase contracts; and

• stock purchase units, each representing ownership of a stock purchase contract and, as security for the holder’s obligation to purchase common stock or preferred stock under the stock purchase contract, any of our other securities being registered hereby or preferred securities or debt obligations of third parties, including U.S. Treasury securities.

DESCRIPTION OF OUR CAPITAL STOCK

Authorized and Outstanding Capital Stock

Pursuant to our Restated Certificate of Incorporation, as amended (our “certificate of incorporation”), our authorized capital stock is 755,000,000 shares, consisting of:

• 5,000,000 shares of preferred stock, par value $0.10 per share, of which 40,000 shares were designated as Series A Junior Participating Preferred Stock; and

• 750,000,000 shares of common stock, par value $0.20 per share.

As of October 28, 2020, we had 178,220,903 outstanding shares of common stock, which excludes unissued shares reserved under various employee compensation plans, shares held by certain of our subsidiaries and shares held in a grantor trust. No shares of preferred stock are currently outstanding.

No holders of any class of our capital stock are entitled to preemptive rights.

In general, the classes of authorized capital stock are afforded preferences with respect to dividends and liquidation rights in the order listed above. Our board of directors is empowered, without approval of our stockholders, to cause the preferred stock to be issued in one or more series, with the numbers of shares of each series and the rights, preferences and limitations of each series to be determined by it. The specific matters that may be determined by our board of directors include the dividend rights, voting rights, redemption rights, liquidation preferences, if any, conversion and exchange rights, retirement and sinking fund provisions and other rights, qualifications, limitations and restrictions of any wholly unissued series of preferred stock, the number of shares constituting that series and the terms and conditions of the issue of the shares.

The following is a summary of the material provisions and features of our certificate of incorporation and our Amended and Restated By-Laws (our “by-laws”). You should refer to our certificate of incorporation and our by-laws for complete information regarding the provisions of our certificate of incorporation and our by-laws, including the definitions of some of the terms used below. Copies of our certificate of incorporation and our by-laws are incorporated by reference as exhibits to the registration statement of which this prospectus forms a part. Whenever particular sections or defined terms of our certificate of incorporation and our by-laws are referred to, such sections or defined terms are incorporated herein by reference, and the statement in connection with which such reference is made is qualified in its entirety by such reference.

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Common Stock

Subject to any preferential rights of any preferred stock created by our board of directors, each outstanding share of our common stock is entitled to such dividends as our board of directors may declare from time to time out of funds that we can legally use to pay dividends. The holders of common stock possess exclusive voting rights, except to the extent our board of directors specifies voting power with respect to any preferred stock that is issued.

Each holder of our common stock is entitled to one vote for each share of common stock and does not have any right to cumulate votes in the election of directors. In the event of liquidation, dissolution or winding-up of W. R. Berkley, holders of our common stock will be entitled to receive on a pro-rata basis any assets remaining after provision for payment of creditors and after payment of any liquidation preferences to holders of preferred stock, if any.

The transfer agent and registrar for our common stock is Wells Fargo Bank, N.A.

Our common stock is listed on the New York Stock Exchange under the symbol “WRB”. All shares of our common stock currently issued and outstanding are fully paid and non-assessable. Shares of our common stock offered by a prospectus supplement, upon issuance against full consideration, will be fully paid and non-assessable. A more detailed description of our common stock is set forth in our registration statement filed under the Exchange Act on Form 8-A/A on May 1, 2001, including any further amendment or report for the purpose of updating such description.

Preferred Stock

The particular terms of any series of preferred stock will be set forth in the prospectus supplement relating to the offering.

The rights, preferences, privileges and restrictions, including dividend rights, voting rights, terms of redemption, retirement and sinking fund provisions and liquidation preferences, if any, of the preferred stock of each series will be fixed or designated pursuant to a certificate of designation adopted by our board of directors or a duly authorized committee of our board of directors. The terms, if any, on which shares of any series of preferred stock are convertible or exchangeable into common stock will also be set forth in the prospectus supplement relating to the offering. These terms may include provisions for conversion or exchange, either mandatory, at the option of the holder, or at our option, in which case the number of shares of common stock to be received by the holders of preferred stock would be calculated as of a time and in the manner stated in the applicable prospectus supplement. The description of the terms of a particular series of preferred stock that will be set forth in the applicable prospectus supplement does not purport to be complete and is qualified in its entirety by reference to the certificate of designation relating to such series.

Provisions of Our Certificate of Incorporation and By-Laws

Provisions of our certificate of incorporation and by-laws may delay or make more difficult unsolicited acquisitions or changes of our control. We believe that these provisions will enable us to develop our business in a manner that will foster long-term growth without disruption caused by the threat of a takeover not thought by our board of directors to be in our best interests and the best interests of our stockholders.

Those provisions could have the effect of discouraging third parties from making proposals involving an unsolicited acquisition or change of control of W. R. Berkley, although the proposals, if made, might be considered desirable by a majority of our stockholders. Those provisions may also have the effect of making it more difficult for third parties to cause the replacement of our current management without the concurrence of our board of directors.

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These provisions include:

• the establishment of a classified board of directors and the ability of our board to increase its size and to appoint directors to fill newly created directorships;

• the requirement that 80% of our stockholders entitled to vote in the election of directors approve certain transactions between us and certain of our stockholders, including the merger of W. R. Berkley into such certain stockholder, our disposition of substantial assets to such certain stockholder or our exchange of voting securities with such certain stockholder for the sale or lease to us of securities or assets of such certain stockholder;

• the need for advance notice in order to raise business or make nominations at stockholders’ meetings; and

• the availability of capital stock for issuance from time to time at the discretion of our board of directors (see “— Authorized and Outstanding Capital Stock” and “— Preferred Stock”).

See “— Restrictions on Ownership Under Insurance Laws,” and “— Delaware General Corporation Law” for other provisions applicable to us that may discourage takeovers.

Classified Board of Directors; Number of Directors; Filling of Vacancies

Our certificate of incorporation and by-laws provide for a board of directors divided into three classes, with one class being elected each year to serve for a three-year term. As a result, at least two annual meetings of stockholders may be required for stockholders to change a majority of our board of directors. Our certificate of incorporation and by-laws also provide that newly created directorships resulting from any increase in the authorized number of up to 15 directors, or any vacancy, may be filled by a vote of a majority of directors then in office. Accordingly, our board of directors may be able to prevent any stockholder from obtaining majority representation on the board of directors by increasing the size of the board and filling the newly created directorships with its own nominees. Directors may be removed at any time for cause by the majority vote of the directors then in office. Additionally, directors may be removed with or without cause by the vote or consent of 80% of our stockholders entitled to vote in the election of directors.

Stockholder Approval of Certain Transactions Effecting a Change of Control

The affirmative vote or consent of 80% of our stockholders entitled to vote in the election of directors is required to authorize any of the following transactions:

• our merger or consolidation into any other corporation or entity;

• the sale, lease, exchange, mortgage or other disposition of all or any substantial part of our assets to any other corporation, person or other entity; or

• the sale or lease by any other corporation, person or entity to us or any of our subsidiaries of any securities or assets, except assets having an aggregate fair market value of less than $4,000,000, in exchange for our or any of our subsidiaries’ voting securities, including securities convertible into voting securities or options and warrants or rights to purchase voting securities;

if such corporation, person or entity is, or has been at any time within the preceding two years, the beneficial owner of 5% or more of the outstanding shares of our stock entitled to vote in the elections of directors. These transactions do not require an 80% stockholder vote if (a) our board of directors approved a memorandum of understanding with the other corporation prior to the time the other corporation became a beneficial owner of 5% or more of the outstanding shares of our stock entitled to vote in the elections of directors or (b) a majority of the outstanding shares of all classes of stock entitled to vote in elections of directors of the target corporation is owned by us.

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Advance Notice for Raising Business or Making Nominations at Meetings

Our by-laws establish an advance notice procedure for stockholder proposals to be brought before an annual or special meeting of stockholders and for nominations by stockholders of candidates for election as directors at an annual or special meeting at which directors are to be elected. Only such business may be conducted at a special meeting of stockholders as has been specified in our notice to stockholders of such meeting, which notice will be given not less than 10 nor more than 60 days before the date of the meeting. Only such business may be conducted at an annual meeting of stockholders as has been brought before the meeting by, or at the direction of, the board of directors, or by a stockholder who has given to the secretary of W. R. Berkley timely written notice, in proper form, of the stockholder’s intention to bring that business before the meeting. The Executive Chairman of the meeting will have the authority to make all determinations with respect to these matters. Only persons who are nominated by, or at the direction of, the board of directors, or who are nominated by a stockholder who has given timely written notice, in proper form, to the secretary prior to a meeting at which directors are to be elected will be eligible for election as directors.

To be timely, notice of business to be brought before an annual meeting, or nominations of candidates for election as directors at an annual meeting, is required to be received by the secretary of W. R. Berkley not less than 60 days nor more than 90 days in advance of the anniversary date of the immediately preceding annual meeting. In the event that the date of the annual meeting is advanced by more than 30 days or delayed by more than 60 days from such anniversary date, notice by the stockholder to be timely must be so delivered not earlier than the ninetieth day prior to such annual meeting and not later than the close of business on the later of the sixtieth day prior to such annual meeting or the tenth day following the day on which public announcement of the date of such meeting is first made.

Similarly, notice of nominations to be brought before a special meeting of stockholders for the election of directors is required to be delivered to the secretary not earlier than the ninetieth day prior to such special meeting and not later than the close of business on the later of the sixtieth day prior to such special meeting or the tenth day following the day on which public announcement of the date of such meeting is first made.

The notice of any nomination for election as a director is required to set forth:

• as to each person whom the stockholder proposes to nominate for election or reelection as a director, all information relating to such person that is required to be disclosed in solicitations of proxies for election of directors, or is otherwise required, in each case pursuant to Regulation 14A under the Exchange Act, or any successor rule or regulation; and

• as to the stockholder giving the notice and the beneficial owner, if any, on whose behalf the nomination is made (1) the name and address of such stockholder, as they appear on our books, and of such beneficial owner, and (2) the class and number of our shares which are owned beneficially and of record by such stockholder and such beneficial owner.

Restrictions on Ownership Under Insurance Laws

Although our certificate of incorporation and by-laws do not contain any provision restricting ownership as a result of the application of various state insurance laws, these laws will be a significant deterrent to any person interested in acquiring our control. The insurance holding company laws of each of the jurisdictions in which our insurance subsidiaries are incorporated or commercially domiciled, as well as state corporation laws, govern any acquisition of control of our insurance subsidiaries or of us. In general, these laws provide that no person or entity may directly or indirectly acquire control of an insurance company unless that person or entity has received the prior approval of the insurance regulatory authorities. An acquisition of control generally would be presumed in the case of any person or entity who purchases 10% or more of our outstanding common stock, unless the applicable insurance regulatory authorities determine otherwise.

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Delaware General Corporation Law

The terms of Section 203 of the Delaware General Corporation Law apply to us since we are a Delaware corporation and our certificate of incorporation does not exclude us from the restrictions imposed thereunder. Pursuant to Section 203, with certain exceptions, a Delaware corporation may not engage in any of a broad range of business combinations, such as mergers, consolidations and sales of assets, with an “interested stockholder,” as defined below, for a period of three years from the date that such person became an interested stockholder unless:

• the transaction that results in a person becoming an interested stockholder, or the business combination is approved by the board of directors of the corporation before the person becomes an interested stockholder;

• upon consummation of the transaction which results in the stockholder becoming an interested stockholder, the interested stockholder owns 85% or more of the voting stock of the corporation outstanding at the time the transaction commenced, excluding shares owned by persons who are directors and also officers, and shares owned by certain employee stock plans; or

• on or after the time the person becomes an interested stockholder, the business combination is approved by the corporation’s board of directors and by holders of at least two-thirds of the corporation’s outstanding voting stock, excluding shares owned by the interested stockholder, at a meeting of stockholders.

Under Section 203, an “interested stockholder” is defined as any person, other than the corporation and any direct or indirect majority-owned subsidiary, that is:

• the owner of 15% or more of the outstanding voting stock of the corporation; or

• an affiliate or associate of the corporation and was the owner of 15% or more of the outstanding voting stock of the corporation at any time within the three-year period immediately prior to the date on which it is sought to be determined whether such person is an interested stockholder.

Under certain circumstances, Section 203 makes it more difficult for a person who would be an interested stockholder to effect various business combinations with a corporation for a three-year period, although the stockholders may elect to exclude a corporation from the restrictions imposed thereunder. The provisions of Section 203 may encourage companies interested in acquiring us to negotiate in advance with our board of directors, because the stockholder approval requirement would be avoided if a majority of the directors then in office approved either the business combination or the transaction resulting in the stockholder becoming an interested stockholder. These provisions also may have the effect of preventing changes in our management. It is further possible that such provisions could make it more difficult to accomplish transactions that stockholders may otherwise deem to be in their best interest.

Limitations on Director Liability

Our certificate of incorporation contains a provision that is designed to limit our directors’ liability to the extent permitted by the Delaware General Corporation Law and any amendments to that law. Specifically, directors will not be held liable to the Company or its stockholders for monetary damages for an act or omission in their capacity as a director, except for liability as a result of:

• a breach of the duty of loyalty to the Company or our stockholders;

• acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law;

• payment of an improper dividend or improper redemption or repurchase of the Company’s stock under Section 174 of the Delaware General Corporation Law; or

• any transaction from which the director received an improper personal benefit.

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The principal effect of the limitation on liability provision is that a stockholder is unable to prosecute an action for monetary damages against a director of the Company unless the stockholder can demonstrate one of the specified bases for liability. This provision, however, does not eliminate or limit director liability arising in connection with causes of action brought under the federal securities laws. Our certificate of incorporation also does not eliminate our directors’ duty of care. The inclusion of the limitation on liability provision in the certificate may, however, discourage or deter stockholders or management from bringing a lawsuit against directors for a breach of their fiduciary duties, even though such an action, if successful, might otherwise have benefited the Company and our stockholders. This provision should not affect the availability of equitable remedies such as injunction or rescission based upon a director’s breach of the duty of care.

Our by-laws also provide that we shall indemnify our directors and officers to the fullest extent permitted by Delaware law. We are required to indemnify our directors and officers for all judgments, fines, amounts paid in settlement, legal fees and other expenses reasonably incurred in connection with pending or threatened legal proceedings because of the director’s or officer’s position with the Company or another entity that the director or officer serves at our request, subject to certain conditions, and to advance funds to our directors and officers to enable them to defend against such proceedings. To receive indemnification, the director or officer must succeed in the legal proceeding or act in good faith and in a manner reasonably believed to be in or not opposed to the best interests of the Company and with respect to any criminal action or proceeding, in a manner he or she reasonably believed to be lawful.

DESCRIPTION OF THE DEPOSITARY SHARES

General

We may, at our option, elect to offer depositary shares, representing fractional interests in debt securities or fractional shares of our common stock or a particular series of our preferred stock, as described below. In the event we elect to do so, depositary receipts evidencing depositary shares will be issued to the public.

The interests in a security of a particular series of debt securities or shares of common stock or any class or series of preferred stock represented by depositary shares will be deposited under a deposit agreement among us, a depositary selected by us and the holders of the depositary receipts. The depositary will be a bank or trust company having its principal office in the United States and having a combined capital and surplus of at least $50,000,000. Subject to the terms of the deposit agreement, each owner of a depositary share will be entitled, in proportion to the applicable fraction of a debt security or share of common stock or preferred stock represented by such depositary share, to all the rights and preferences of the debt security, common stock or preferred stock, as the case may be, represented by the depositary share, including dividend, voting, conversion, redemption, sinking fund, repayment at maturity, subscription and liquidation rights.

The depositary shares will be evidenced by depositary receipts issued pursuant to the deposit agreement. Depositary receipts will be distributed to those persons purchasing the fractional interests in debt securities or fractional shares of common stock or preferred stock in accordance with the terms of the offering described in the related prospectus supplement. If we issue depositary shares, we will file copies of the forms of deposit agreement and depositary receipt as exhibits to the registration statement of which this prospectus forms a part.

Pending the preparation of definitive depositary receipts, the depositary may, upon our written order, issue temporary depositary receipts substantially identical to, and entitling the holders thereof to all the rights pertaining to, the definitive depositary receipts but not in definitive form. Definitive depositary receipts will be prepared thereafter without unreasonable delay, and temporary depositary receipts will be exchangeable for definitive depositary receipts without charge to the holder thereof.

The following description of the depositary shares sets forth the material terms and provisions of the depositary shares to which any prospectus supplement may relate. The particular terms of the depositary shares

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offered by any prospectus supplement, and the extent to which the general provisions described below may apply to the offered securities, will be described in the prospectus supplement.

Dividends and Other Distributions

The depositary will distribute all payments of interest, cash dividends or other cash distributions received in respect of the debt securities, common stock or class or series of preferred stock, as the case may be, to the record holders of depositary shares relating to such debt securities, common stock or class or series of preferred stock in proportion to the number of such depositary shares owned by such holders.

In the event of a distribution other than in cash, the depositary will distribute property received by it to the record holders of depositary shares entitled thereto, unless the depositary determines that it is not feasible to make such distribution, in which case the depositary may, with our approval, sell such property and distribute the net proceeds from such sale to such holders.

Withdrawal of Shares

Upon surrender of the depositary receipts at the corporate trust office of the depositary (unless the related depositary shares have previously been called for redemption), the holder of the depositary shares evidenced thereby is entitled to delivery of the number of whole shares of the related common stock or class or series of preferred stock or any debt securities represented by such depositary shares. Holders of depositary shares will be entitled to receive whole shares of the related common stock or class or series of preferred stock or debt securities on the basis set forth in the prospectus supplement for such common stock or class or series of preferred stock or debt securities, but holders of such whole common stock or preferred stock or such debt securities will not thereafter be entitled to exchange them for depositary shares. If the depositary receipts delivered by the holder evidence a number of depositary shares in excess of the number of depositary shares representing the number of whole common stock or preferred stock or debt securities to be withdrawn, the depositary will deliver to such holder at the same time a new depositary receipt evidencing such excess number of depositary shares. In no event will fractional common shares or preferred shares or fractional interests in debt securities be delivered upon surrender of depositary receipts to the depositary.

Redemption of Depositary Shares

Whenever we redeem a debt security, common stock or preferred stock held by the depositary, the depositary will redeem as of the same redemption date the number of depositary shares representing interests in the debt securities or shares of the common stock or preferred stock so redeemed. The redemption price per depositary share will be equal to the applicable fraction of the redemption price per debt security or share of common stock or preferred stock, as the case may be, payable with respect to such redeemed series of debt securities, common stock or preferred stock. If less than all the depositary shares are to be redeemed, the depositary shares to be redeemed will be selected by lot or pro rata, as may be determined by the depositary.

Exercise of Rights under the Indenture or Voting the Common Stock or Preferred Stock

Upon receipt of notice of any meeting at which the holders of the debt securities, common stock or preferred stock, as the case may be, are entitled to vote or respond to requests for instructions or directions, the depositary will transmit the information contained in such notice of meeting to the record holders of the depositary shares relating to such debt securities, common stock or preferred stock. Each record holder of such depositary shares on the record date will be entitled to instruct the depositary how to give instructions or directions with respect to the debt securities represented by such holder’s depositary shares or how to vote the amount of common stock or preferred stock represented by such holder’s depositary shares. The record date for the depositary shares will be the same date as the record date for the debt securities, common stock or preferred stock, as the case may be. The depositary will endeavor, insofar as practicable, to give instructions or directions with respect to the debt

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securities or vote the number of shares of common stock or preferred stock, as the case may be, represented by the depositary shares in accordance with such instructions, and we will agree to take all action which the depositary deems necessary in order to enable the depositary to do so. The depositary will abstain from giving instructions or directions with respect to fractional interests in the debt securities or voting shares of the common stock or preferred stock, as the case may be, to the extent it does not receive specific instructions from the holders of depositary shares representing such debt securities or shares of common stock or preferred stock.

Amendment and Termination of the Deposit Agreement

The form of depositary receipt evidencing the depositary shares and any provision of the deposit agreement may at any time be amended by agreement between us and the depositary. However, any amendment which materially and adversely alters the rights of the holders of depositary receipts will not be effective unless such amendment has been approved by the holders of depositary receipts representing at least a majority of the depositary shares then outstanding. Additionally, unless otherwise provided in the related prospectus supplement, in the case of amendments relating to or affecting rights to receive interest, dividends or distributions or instruction, direction, voting, repayment or redemption rights, approval is required by the holders of depositary receipts representing 66²/₃% of the depositary shares then outstanding. The deposit agreement may be terminated by us or the depositary only if:

• all outstanding depositary shares have been redeemed;

• if applicable, the debt securities and the preferred stock represented by depository shares have been converted into or exchanged for our common stock;

• there has been a complete repayment or redemption of the debt securities or a final distribution in respect of the common stock or preferred stock, including in connection with our liquidation, dissolution or winding-up, and such repayment, redemption or distribution proceeds, as the case may be, has been distributed to the holders of depositary receipts; or

• upon the consent of holders of depositary receipts representing not less than 66²/₃% of the depositary shares outstanding.

Charges of Depositary

We will pay all transfer and other taxes and governmental charges arising solely from the existence of the depositary arrangements. We will also pay charges of the depositary in connection with the initial deposit of the debt securities, common stock or preferred stock, as the case may be and any repayment or redemption of such debt securities, common stock or preferred stock, as the case may be. Holders of depositary receipts will pay all other transfer and other taxes and governmental charges and such other charges as are expressly provided in the deposit agreement to be for their accounts.

The depositary may refuse to effect any transfer of a depositary receipt or any withdrawal of debt securities or shares of common stock or preferred stock evidenced thereby until all such taxes and charges with respect to such depositary receipt or such debt securities or shares of common stock or preferred stock are paid by the holders thereof.

Miscellaneous

The depositary will forward all reports and communications from us which are delivered to the depositary and which we are required to furnish to the holders of debt securities, common stock or preferred stock, as the case may be.

Neither we nor the depositary will be liable if either is prevented or delayed by law or any circumstance beyond its control in performing its obligations under the deposit agreement. Our obligations and the obligations

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of the depositary under the deposit agreement will be limited to performance in good faith of our and their respective duties thereunder and neither we nor the depositary will be obligated to prosecute or defend any legal proceeding in respect of any depositary shares, debt securities, common stock or preferred stock unless satisfactory indemnity is furnished. We and the depositary may rely on written advice of counsel or accountants, or information provided by persons presenting debt securities or shares of common stock or preferred stock for deposit, holders of depositary shares or other persons believed to be competent and on documents believed to be genuine.

Resignation and Removal of Depositary

The depositary may resign at any time by delivering to us notice of its election to do so, and we may at any time remove the depositary. Any such resignation or removal of the depositary will take effect upon the appointment of a successor depositary, which successor depositary must be appointed within 60 days after delivery of the notice of resignation or removal and must be a bank or trust company having its principal office in the United States and having a combined capital and surplus of at least $50,000,000.

DESCRIPTION OF THE DEBT SECURITIES

The following description of our debt securities sets forth the material terms and provisions of the debt securities to which any prospectus supplement may relate. Our senior debt securities are to be issued under an indenture between us and The Bank of New York Mellon, as trustee, the form of which is incorporated by reference as an exhibit to the registration statement of which this prospectus forms a part. We refer to this indenture in this prospectus as the “senior indenture.” Our subordinated debt securities are to be issued under an indenture which we sometimes refer to in this prospectus as the “subordinated indenture” between us and The Bank of New York Mellon, as trustee, the form of which is incorporated by reference to the registration statement of which this prospectus forms a part. The senior indenture and the subordinated indenture are sometimes referred to herein collectively as the “W. R. Berkley indentures” and each individually as a “W. R. Berkley indenture.” The particular terms of the debt securities offered by any prospectus supplement, and the extent to which the general provisions described below may apply to the offered debt securities, will be described in the applicable prospectus supplement.

The following are summaries of the material terms and provisions of the W. R. Berkley indentures and the related debt securities. You should refer to the forms of the W. R. Berkley indentures and the debt securities for complete information regarding the terms and provisions of the W. R. Berkley indentures, including the definitions of some of the terms used below, and the debt securities. Wherever particular articles, sections or defined terms of a W. R. Berkley indenture are referred to, those articles, sections or defined terms are incorporated herein by reference, and the statement in connection with which such reference is made is qualified in its entirety by such reference. Wherever particular articles, sections or defined terms of a W. R. Berkley indenture, without specific reference to a particular W. R. Berkley indenture, are referred to, those articles, sections or defined terms are contained in all W. R. Berkley indentures. The senior indenture and the subordinated indenture are substantially identical, except for certain covenants of ours and provisions relating to subordination.

General

The W. R. Berkley indentures do not limit the aggregate principal amount of the debt securities which we may issue thereunder and provide that we may issue the debt securities thereunder from time to time in one or more series. (Section 3.1) The W. R. Berkley indentures do not limit the amount of other Indebtedness or the debt securities, other than certain secured Indebtedness as described below, which we or our Subsidiaries may issue.

Unless otherwise provided in a prospectus supplement, the senior debt securities will be unsecured obligations of ours and will rank equally with all of our other unsecured and unsubordinated indebtedness. The

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subordinated debt securities will be unsecured obligations of ours, subordinated in right of payment to the prior payment in full of all Senior Indebtedness of ours as described below under “Subordination of the Subordinated Debt Securities” and in the applicable prospectus supplement. The W. R. Berkley indentures do not limit the amount of senior, pari passu and junior Indebtedness that we may issue.

As of September 30, 2020, we had outstanding approximately $1,614 million face value of senior notes and other debt, in addition to $1,485 million face value of subordinated debentures.

Because we are a holding company, our rights and the rights of our creditors, including the holders of our debt securities, and stockholders to participate in any distribution of assets of any Subsidiary upon the Subsidiary’s liquidation or reorganization or otherwise would be subject to the prior claims of the Subsidiary’s creditors, except to the extent that we may ourselves be a creditor with recognized claims against the Subsidiary. The rights of our creditors, including the holders of our debt securities, to participate in the distribution of stock owned by us in certain of the Subsidiaries, including our insurance Subsidiaries, may also be subject to approval by certain insurance regulatory authorities having jurisdiction over such Subsidiaries. As of September 30, 2020, our Subsidiaries had approximately $117 million of indebtedness for borrowed money.

The prospectus supplement relating to the particular debt securities offered thereby will describe the following terms of the offered debt securities:

• the title of such debt securities and the series in which such debt securities will be included, which may include medium-term notes;

• any limit upon the aggregate principal amount of such debt securities;

• the date or dates, or the method or methods, if any, by which such date or dates will be determined, on which the principal of such debt securities will be payable;

• the rate or rates at which such debt securities will bear interest, if any, which rate may be zero in the case of certain debt securities issued at an issue price representing a discount from the principal amount payable at maturity, or the method by which such rate or rates will be determined, including, if applicable, any remarketing option or similar method, and the date or dates from which such interest, if any, will accrue or the method by which such date or dates will be determined;

• the date or dates on which interest, if any, on such debt securities will be payable and any regular record dates applicable to the date or dates on which interest will be so payable;

• the place or places where the principal of, any premium or interest on or any additional amounts with respect to such debt securities will be payable, any of such debt securities that are issued in registered form may be surrendered for registration of transfer or exchange, and any such debt securities may be surrendered for conversion or exchange;

• whether any of such debt securities are to be redeemable at our option, whether we will be obligated to redeem or purchase any of such debt securities pursuant to any sinking fund or analogous provision or at the option of any holder thereof, and the terms of such option or obligation, as described under “— Redemption” below;

• if other than denominations of $1,000 and any integral multiple thereof, the denominations in which any debt securities to be issued in registered form will be issuable and, if other than a denomination of $5,000, the denominations in which any debt securities to be issued in bearer form will be issuable;

• whether the debt securities will be convertible into common stock and/or exchangeable for other securities and, if so, the terms and conditions upon which such debt securities will be so convertible or exchangeable;

• if other than the principal amount, the portion of the principal amount, or the method by which such portion will be determined, of such debt securities that will be payable upon declaration of acceleration of the maturity thereof;

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• if other than United States dollars, the currency of payment, including composite currencies, of the principal of, any premium or interest on or any additional amounts with respect to any of such debt securities;

• whether the principal of, any premium or interest on or any additional amounts with respect to such debt securities will be payable, at our election or the election of a holder, in a currency other than that in which such debt securities are stated to be payable and the date or dates on which, the period or periods within which, and the other terms and conditions upon which, such election may be made;

• any index, formula or other method used to determine the amount of payments of principal of, any premium or interest on or any additional amounts with respect to such debt securities;

• �� whether such debt securities are to be issued in the form of one or more global securities and, if so, the identity of the depositary for such global security or securities;

• whether such debt securities are senior debt securities or subordinated debt securities and, if subordinated debt securities, the specific subordination provisions applicable thereto;

• in the case of subordinated debt securities, the relative degree, if any, to which such subordinated debt securities of the series will be senior to or be subordinated to other series of the subordinated debt securities or other indebtedness of ours in right of payment, whether such other series of the subordinated debt securities or other indebtedness are outstanding or not;

• any modifications of or additions to the Events of Default or covenants of ours with respect to such debt securities;

• whether the provisions described below under “Discharge, Defeasance and Covenant Defeasance” will be applicable to such debt securities;

• whether any of such debt securities are to be issued upon the exercise of warrants, and the time, manner and place for such debt securities to be authenticated and delivered; and

• any other terms of such debt securities and any modifications or additions to the applicable W. R. Berkley indenture in respect of such debt securities. (Section 3.1)

We will have the ability under the W. R. Berkley indentures to “reopen” a previously issued series of the debt securities and issue additional debt securities of that series or establish additional terms of that series. We are also permitted to issue debt securities with the same terms as previously issued debt securities. (Section 3.1)

Unless otherwise provided in the related prospectus supplement, principal, premium, interest and additional amounts, if any, with respect to any debt securities will be payable at the office or agency maintained by us for such purposes. In the case of debt securities issued in registered form, interest may be paid by check mailed to the persons entitled thereto at their addresses appearing on the security register or by transfer to an account maintained by the payee with a bank located in the United States. Interest on debt securities issued in registered form will be payable on any interest payment date to the persons in whose names the debt securities are registered at the close of business on the regular record date with respect to such interest payment date. All paying agents initially designated by us for the debt securities will be named in the related prospectus supplement. We may at any time designate additional paying agents or rescind the designation of any paying agent or approve a change in the office through which any paying agent acts, except that we will be required to maintain a paying agent in each place where the principal of, any premium or interest on or any additional amounts with respect to the debt securities are payable. (Sections 3.7 and 10.2)

Unless otherwise provided in the related prospectus supplement, the debt securities may be presented for transfer or exchanged for other debt securities of the same series, containing identical terms and provisions, in any authorized denominations, and of a like aggregate principal amount, at the office or agency maintained by us for such purposes. Such transfer or exchange will be made without service charge, but we may require payment

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of a sum sufficient to cover any tax or other governmental charge and any other expenses then payable. We will not be required to:

• issue, register the transfer of, or exchange, the debt securities during a period beginning at the opening of business 15 days before the day of transmittal of a notice of redemption of any such debt securities and ending at the close of business on the day of such transmittal; or

• register the transfer of or exchange any debt security so selected for redemption in whole or in part, except the unredeemed portion of any debt security being redeemed in part. (Section 3.5)

We have appointed the trustee as security registrar. Any transfer agent, in addition to the security registrar, initially designated by us for any debt securities will be named in the related prospectus supplement. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place where the principal of, any premium or interest on or any additional amounts with respect to the debt securities are payable. (Section 10.2)

Unless otherwise provided in the related prospectus supplement, the debt securities will be issued only in fully registered form without coupons in minimum denominations of $1,000 and any integral multiple thereof. (Section 3.2) The debt securities may be represented in whole or in part by one or more global debt securities registered in the name of a depositary or its nominee and, if so represented, interests in such global debt security will be shown on, and transfers thereof will be effected only through, records maintained by the designated depositary and its participants as described below. Where the debt securities of any series are issued in bearer form, the special restrictions and considerations, including special offering restrictions and special United States Federal income tax considerations, applicable to such debt securities and to payment on and transfer and exchange of such debt securities will be described in the related prospectus supplement.

The debt securities may be issued as original issue discount securities, bearing no interest or bearing interest at a rate which at the time of issuance is below market rates, to be sold at a substantial discount below their principal amount. Special United States Federal income tax and other considerations applicable to original issue discount securities will be described in the related prospectus supplement.

If the purchase price of any debt securities is payable in one or more foreign currencies or currency units or if any debt securities are denominated in one or more foreign currencies or currency units or if the principal of, or any premium or interest on, or any additional amounts with respect to, any debt securities is payable in one or more foreign currencies or currency units, the restrictions, elections, certain United States Federal income tax considerations, specific terms and other information with respect to such debt securities and such foreign currency or currency units will be set forth in the related prospectus supplement.

We will comply with Section 14(e) under the Exchange Act, and any other tender offer rules under the Exchange Act which may then be applicable, in connection with any obligation of ours to purchase debt securities at the option of the holders. Any such obligation applicable to a series of debt securities will be described in the related prospectus supplement.

Unless otherwise described in a prospectus supplement relating to any debt securities, the W. R. Berkley indentures do not contain any provisions that would limit our ability to incur indebtedness or that would afford holders of the debt securities protection in the event of a sudden and significant decline in our credit quality or a takeover, recapitalization or highly leveraged or similar transaction involving us. Accordingly, we could in the future enter into transactions that could increase the amount of indebtedness outstanding at that time or otherwise affect our capital structure or credit rating. You should refer to the prospectus supplement relating to a particular series of the debt securities for information regarding any modifications of or additions to the Events of Default described below or our covenants contained in the W. R. Berkley indentures, including any addition of a covenant or other provisions providing event risk or similar protection.

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Conversion and Exchange

The terms, if any, on which debt securities of any series are convertible into or exchangeable for common stock, preferred stock or other securities, property or cash, or a combination of any of the foregoing, will be set forth in the related prospectus supplement. Such terms may include provisions for conversion or exchange, either mandatory, at the option of the holder, or at our option, in which the securities, property or cash to be received by the holders of the debt securities would be calculated according to the factors and at such time as described in the related prospectus supplement.

Global Securities

The debt securities of a series may be issued in whole or in part in the form of one or more global debt securities that will be deposited with, or on behalf of, a depositary identified in the prospectus supplement relating to such series.

The specific terms of the depositary arrangement with respect to a series of the debt securities will be described in the prospectus supplement relating to such series. We anticipate that the following provisions will apply to all depositary arrangements.

Upon the issuance of a global security, the depositary for such global security or its nominee will credit, on its book-entry registration and transfer system, the respective principal amounts of the debt securities represented by such global security. Such accounts will be designated by the underwriters or agents with respect to such debt securities or by us if such debt securities are offered and sold directly by us. Ownership of beneficial interests in a global security will be limited to persons that may hold interests through participants. Ownership of beneficial interests in such global security will be shown on, and the transfer of that ownership will be effected only through, records maintained by the depositary or its nominee with respect to interests of participants, and on the records of participants with respect to interests of persons other than participants. The laws of some states require that certain purchasers of securities take physical delivery of such securities in definitive form. Such limits and such laws may impair the ability to transfer beneficial interests in a global security.

So long as the depositary for a global security, or its nominee, is the registered owner of such global security, such depositary or such nominee, as the case may be, will be considered the sole owner or holder of the debt securities represented by such global security for all purposes under the applicable W. R. Berkley indenture. Except as described below, owners of beneficial interests in a global security will not be entitled to have the debt securities of the series represented by such global security registered in their names and will not receive or be entitled to receive physical delivery of the debt securities of that series in definitive form.

Principal of, any premium and interest on, and any additional amounts with respect to, the debt securities registered in the name of a depositary or its nominee will be made to the depositary or its nominee, as the case may be, as the registered owner of the global security representing such debt securities. None of the trustee, any paying agent, the security registrar or us will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests of the global security for such debt securities or for maintaining, supervising or reviewing any records relating to such beneficial ownership interests.

We expect that the depositary for a series of the debt securities or its nominee, upon receipt of any payment with respect to such debt securities, will credit immediately participants’ accounts with payments in amounts proportionate to their respective beneficial interest in the principal amount of the global security for such debt securities as shown on the records of such depositary or its nominee. We also expect that payments by participants to owners of beneficial interests in such global security held through such participants will be governed by standing instructions and customary practices, as is now the case with securities held for the accounts of customers registered in “street name,” and will be the responsibility of such participants.

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The W. R. Berkley indentures provide that if:

• the depositary for a series of the debt securities notifies us that it is unwilling or unable to continue as depositary or if such depositary ceases to be eligible under the applicable W. R. Berkley indenture and a successor depositary is not appointed by us within 90 days of written notice;

• we determine that the debt securities of a particular series will no longer be represented by global securities and we execute and deliver to the trustee a company order to such effect; or

• an Event of Default with respect to a series of the debt securities has occurred and is continuing,

then, in an such case, the global securities will be exchanged for the debt securities of such series in definitive form of like tenor and of an equal aggregate principal amount, in authorized denominations. Such definitive debt securities will be registered in such name or names as the depositary shall instruct the trustee. (Section 3.5) It is expected that such instructions may be based upon directions received by the depositary from participants with respect to ownership of beneficial interests in global securities.

Payment of Additional Amounts

We will make all payments of principal of, and premium, if any, interest and any other amounts on, or in respect of, the debt securities of any series without withholding or deduction at source for, or on account of, any present or future taxes, fees, duties, assessments or governmental charges of whatever nature imposed or levied by or on behalf of a taxing jurisdiction or any political subdivision or taxing authority thereof or therein, unless such taxes, fees, duties, assessments or governmental charges are required to be withheld or deducted by:

• the laws, or any regulations or rulings promulgated thereunder, of a taxing jurisdiction or any political subdivision or taxing authority thereof or therein; or

• an official position regarding the application, administration, interpretation or enforcement of any such laws, regulations or rulings, including, without limitation, a holding by a court of competent jurisdiction or by a taxing authority in a taxing jurisdiction or any political subdivision thereof.

If a withholding or deduction at source is required, we will, subject to certain limitations and exceptions described below, pay to the holder of any such debt security such additional amounts as may be necessary so that every net payment of principal, premium, if any, interest or any other amount made to such holder, after the withholding or deduction, will not be less than the amount provided for in such debt security and the applicable W. R. Berkley indenture to be then due and payable.

We will not be required to pay any additional amounts for or on account of:

(1) any tax, fee, duty, assessment or governmental charge of whatever nature which would not have been imposed but for the fact that such holder:

• was a resident, domiciliary or national of, or engaged in business or maintained a permanent establishment or was physically present in, the relevant taxing jurisdiction or any political subdivision thereof or otherwise had some connection with the relevant taxing jurisdiction other than by reason of the mere ownership of, or receipt of payment under, such debt security;

• presented such debt security for payment in the relevant taxing jurisdiction or any political subdivision thereof, unless such debt security could not have been presented for payment elsewhere; or

• presented such debt security for payment more than 30 days after the date on which the payment in respect of such debt security became due and payable or provided for, whichever is later, except to the extent that the holder would have been entitled to such additional amounts if it had presented such debt security for payment on any day within that 30-day period;

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(2) any estate, inheritance, gift, sale, transfer, personal property or similar tax, assessment or other governmental charge;

(3) any tax, assessment or other governmental charge that is imposed or withheld by reason of the failure by the holder or the beneficial owner of such debt security to comply with any reasonable request by us addressed to the holder within 90 days of such request:

• to provide information concerning the nationality, residence or identity of the holder or such beneficial owner; or

• to make any declaration or other similar claim or satisfy any information or reporting requirement, which is required or imposed by statute, treaty, regulation or administrative practice of the relevant taxing jurisdiction or any political subdivision thereof as a precondition to exemption from all or part of such tax, assessment or other governmental charge; or

(4) any combination of items (1), (2) and (3) above.

In addition, we will not pay additional amounts with respect to any payment of principal of, or premium, if any, interest or any other amounts on, any such debt security to any holder who is a fiduciary, partnership, other fiscally transparent entity or other than the sole beneficial owner of such debt security to the extent such payment would be required by the laws of the relevant taxing jurisdiction, or any political subdivision or relevant taxing authority thereof or therein, to be included in the income for tax purposes of a beneficiary or settlor with respect to such fiduciary, partner, member of such other fiscally transparent entity or a beneficial owner who would not have been entitled to such additional amounts had it been the holder of the debt security. (Section 10.4 of the senior indenture and the subordinated indenture)

Redemption

If provided in the related prospectus supplement, we will have the right to redeem some or all of the debt securities. The prospectus supplement relating to the particular debt securities offered thereby will describe:

• whether and on what terms we will have the option to redeem such debt securities in lieu of paying additional amounts in respect of certain taxes, fees, duties, assessments or governmental charges that might be imposed on holders of such debt securities;

• whether any of such debt securities are to be redeemable at our option and, if so, the date or dates on which, the period or periods within which, the price or prices at which and the other terms and conditions upon which such debt securities may be redeemed, in whole or in part, at our option; and

• whether we will be obligated to redeem or purchase any of such debt securities pursuant to any sinking fund or analogous provision or at the option of any holder thereof and, if so, the date or dates on which, the period or periods within which, the price or prices at which and the other terms and conditions upon which such debt securities will be redeemed or purchased, in whole or in part, pursuant to such obligation, and any provisions for the remarketing of such debt securities so redeemed or purchased.

If provided in the related prospectus supplement, the holders of the debt securities may have the right to cause us to repay their indebtedness upon a change of control of W. R. Berkley.

Each W. R. Berkley indenture provides that if we do not redeem all of the debt securities thereunder, the securities to be redeemed will be selected in accordance with the procedures of the depositary. If any debt securities are to be redeemed in part only, we will issue a new note for such securities in principal amount equal to the unredeemed principal portion. If a portion of your debt securities is selected for partial redemption and you convert or elect repurchase of a portion of your securities, the converted or repurchased portion will be deemed to be taken from the portion selected for redemption. Unless otherwise provided in the prospectus supplement, notice of redemption setting forth the redemption date and redemption price must be given at least thirty days and not more than sixty days prior to the redemption date.

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Notice of any redemption will be transmitted at least 30 days but not more than 60 days before the redemption date to each holder of subordinated debt securities to be redeemed at its registered address. Unless we default in payment of the redemption price, on and after the redemption date interest will cease to accrue on the subordinated debt securities or portions thereof called for redemption.

Consolidation, Amalgamation, Merger and Sale of Assets

Each W. R. Berkley indenture provides that we may not:

(1) consolidate or amalgamate with or merge into any Person or convey, transfer or lease our properties and assets as an entirety or substantially as an entirety to any Person; or

(2) permit any Person to consolidate or amalgamate with or merge into us, or convey, transfer or lease its properties and assets as an entirety or substantially as an entirety to us, unless:

• in the case of (1) above, such Person is organized and existing under the laws of the United States of America, any State thereof or the District of Columbia, Bermuda, the Cayman Islands, Ireland, Switzerland, the United Kingdom or any other country which is on the date of such W.R. Berkley indenture a member of the Organization of Economic Cooperation and Development, and will expressly assume, by supplemental indenture satisfactory in form to the trustee, the due and punctual payment of the principal of, any premium and interest on and any additional amounts with respect to all of the debt securities issued thereunder, and the performance of our obligations under such W. R. Berkley indenture and the debt securities issued thereunder, and provides for conversion or exchange rights in accordance with the provisions of the debt securities of any series that are convertible or exchangeable into common stock or other securities;

• immediately after giving effect to such transaction and treating any indebtedness which becomes an obligation of ours or a Subsidiary as a result of such transaction as having been incurred by us or such Subsidiary at the time of such transaction, no Event of Default, and no event which after notice or lapse of time or both would become an Event of Default, will have happened and be continuing; and

• certain other conditions are satisfied. (Section 8.1)

Events of Default

Except as otherwise provided in the related prospectus supplement and specifically deleted or modified in or pursuant to the related supplemental indenture, board resolution or officer’s certificate establishing the terms of any series of debt securities pursuant to the applicable W. R. Berkley indenture, each of the following events will constitute an Event of Default under the applicable W. R. Berkley indenture with respect to any series of debt securities issued thereunder, whatever the reason for such Event of Default and whether it will be voluntary or involuntary or be effected by operation of law or pursuant to any judgment, decree or order of any court or any order, rule or regulation of any administrative or governmental body:

(1) default in the payment of any interest on any debt security of such series, or any additional amounts payable with respect thereto, when such interest becomes or such additional amounts become due and payable, and continuance of such default for a period of 30 days;

(2) default in the payment of the principal of or any premium on any debt security of such series, or any additional amounts payable with respect thereto, when such principal or premium becomes or such additional amounts become due and payable either at maturity, upon any redemption, by declaration of acceleration or otherwise;

(3) default in the deposit of any sinking fund payment, when and as due by the terms of any debt security of such series;

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(4) default in the performance, or breach, of any covenant or warranty of ours contained in the applicable W. R. Berkley indenture for the benefit of such series or in the debt securities of such series, and the continuance of such default or breach for a period of 60 days after there has been given written notice as provided in such W. R. Berkley indenture;

(5) if any event of default as defined in any mortgage, indenture or instrument under which there may be issued, or by which there may be secured or evidenced, any Indebtedness of ours, whether such Indebtedness now exists or is hereafter created or incurred, happens and consists of default in the payment of more than $50,000,000 in principal amount of such Indebtedness at the maturity thereof, after giving effect to any applicable grace period, or results in such Indebtedness in principal amount in excess of $50,000,000 becoming or being declared due and payable prior to the date on which it would otherwise become due and payable, and such default is not cured or such acceleration is not rescinded or annulled within a period of 30 days after there has been given written notice as provided in the applicable W. R. Berkley indenture;

(6) we shall fail within 60 days to pay, bond or otherwise discharge any uninsured judgment or court order for the payment of money in excess of $50,000,000, which is not stayed on appeal or is not otherwise being appropriately contested in good faith;

(7) certain events in our bankruptcy, insolvency or reorganization; and

(8) any other Event of Default provided in or pursuant to the applicable W. R. Berkley indenture with respect to the debt securities of such series. (Section 5.1)

If an Event of Default with respect to the debt securities of any series, other than an Event of Default described in (7) of the preceding paragraph, occurs and is continuing, either the trustee or the holders of at least 25% in principal amount of the outstanding debt securities of such series by written notice as provided in the applicable W. R. Berkley indenture may declare the principal amount, or such lesser amount as may be provided for in the debt securities of such series, of all outstanding debt securities of such series to be due and payable immediately. At any time after a declaration of acceleration has been made, but before a judgment or decree for payment of money has been obtained by the trustee, and subject to applicable law and certain other provisions of the applicable W. R. Berkley indenture, the holders of a majority in aggregate principal amount of the debt securities of such series may, under certain circumstances, rescind and annul such acceleration. An Event of Default described in (7) of the preceding paragraph will cause the principal amount and accrued interest, or such lesser amount as provided for in the debt securities of such series, to become immediately due and payable without any declaration or other act by the trustee or any holder. (Section 5.2)

Each W. R. Berkley indenture provides that, within 90 days after the occurrence of any event which is, or after notice or lapse of time or both would become, an Event of Default with respect to the debt securities of any series, the trustee will transmit, in the manner set forth in such W. R. Berkley indenture, notice of such default to the holders of the debt securities of such series unless such default has been cured or waived; provided, however, that the trustee may withhold such notice if and so long as the board of directors, the executive committee or the trust committee of directors and/or responsible officers of the trustee in good faith determine that the withholding of such notice is in the best interest of the holders of the debt securities of such series; and provided, further, that in the case of any default of the character described in (5) of the second preceding paragraph, no such notice to holders will be given until at least 30 days after the default occurs. (Section 6.2)

If an Event of Default occurs and is continuing with respect to the debt securities of any series, the trustee may in its discretion proceed to protect and enforce its rights and the rights of the holders of the debt securities of such series by all appropriate judicial proceedings. (Section 5.3) Each W. R. Berkley indenture provides that, subject to the duty of the trustee during any default to act with the required standard of care, the trustee will be under no obligation to exercise any of its rights or powers under such W. R. Berkley indenture at the request or direction of any of the holders of the debt securities, unless such holders shall have offered to the trustee indemnity reasonably satisfactory to the trustee. (Section 6.1) Subject to such provisions for the indemnification

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of the trustee, and subject to applicable law and certain other provisions of the applicable W. R. Berkley indenture, the holders of a majority in aggregate principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee, with respect to debt securities of such series. (Section 5.12)

Modification and Waiver

We and the trustee may modify or amend a W. R. Berkley indenture with the consent of the holders of not less than a majority in aggregate principal amount of the outstanding debt securities of each series affected thereby; provided, however, that no such modification or amendment may, without the consent of the holder of each outstanding debt security affected thereby:

• change the stated maturity of the principal of, or any premium or installment of interest on, or any additional amounts with respect to, any debt security;

• reduce the principal amount of, or the rate, or modify the calculation of such rate, of interest on, or any additional amounts with respect to, or any premium payable upon the redemption of, any debt security;

• change our obligation to pay additional amounts with respect to any debt security;

• reduce the amount of the principal of an original issue discount security that would be due and payable upon a declaration of acceleration of the maturity thereof or the amount thereof provable in bankruptcy;

• change the redemption provisions of any debt security or adversely affect the right of repayment at the option of any holder of any debt security;

• change the place of payment or the coin or currency in which the principal of, any premium or interest on or any additional amounts with respect to any debt security is payable;

• impair the right to institute suit for the enforcement of any payment on or after the stated maturity of any debt security or, in the case of redemption, on or after the redemption date or, in the case of repayment at the option of any holder, on or after the repayment date;

• reduce the percentage in principal amount of the outstanding debt securities, the consent of whose holders is required in order to take specific actions;

• reduce the requirements for quorum or voting by holders of debt securities in Section 15.4 of the applicable W. R. Berkley indenture;

• modify any of the provisions in the applicable W. R. Berkley indenture regarding the waiver of past defaults and the waiver of certain covenants by the holders of the debt securities except to increase any percentage vote required or to provide that other provisions of such W. R. Berkley indenture cannot be modified or waived without the consent of the holder of each debt security affected thereby;

• make any change that adversely affects the right to convert or exchange any debt security into or for our common stock or other debt securities or other securities, cash or property in accordance with its terms;

• modify any of the provisions of the subordinated indenture relating to the subordination of the subordinated debt securities in a manner adverse to holders of the subordinated debt securities; or

• modify any of the above provisions. (Section 9.2)

In addition, no supplemental indenture may directly or indirectly modify or eliminate the subordination provisions of a subordinated indenture in any manner which might terminate or impair the subordination of the subordinated debt securities to Senior Indebtedness without the prior written consent of the holders of the Senior Indebtedness. (Section 9.7 of the subordinated indenture)

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We and the trustee may modify or amend a W. R. Berkley indenture and the debt securities of any series without the consent of any holder in order to, among other things:

• provide for our successor pursuant to a consolidation, amalgamation, merger or sale of assets;

• add to our covenants for the benefit of the holders of all or any series of debt securities or to surrender any right or power conferred upon us by the applicable W. R. Berkley indenture;

• provide for a successor trustee with respect to the debt securities of all or any series;

• cure any ambiguity or correct or supplement any provision in the applicable W. R. Berkley indenture which may be defective or inconsistent with any other provision, or to make any other provisions with respect to matters or questions arising under the applicable W. R. Berkley indenture which will not adversely affect the interests of the holders of debt securities of any series;

• change the conditions, limitations and restrictions on the authorized amount, terms or purposes of issue, authentication and delivery of debt securities under the applicable W. R. Berkley indenture;

• add any additional Events of Default with respect to all or any series of debt securities;

• secure the debt securities;

• provide for conversion or exchange rights of the holders of any series of debt securities; or

• make any other change that does not materially adversely affect the interests of the holders of any debt securities then outstanding under the applicable W. R. Berkley indenture. (Section 9.1)

The holders of at least a majority in aggregate principal amount of the debt securities of any series may, on behalf of the holders of all debt securities of that series, waive compliance by us with certain restrictive provisions of the applicable W. R. Berkley indenture. (Section 10.6) The holders of not less than a majority in aggregate principal amount of the outstanding debt securities of any series may, on behalf of the holders of all debt securities of that series, waive any past default and its consequences under the applicable W. R. Berkley indenture with respect to debt securities of that series, except a default:

• in the payment of principal of, any premium or interest on or any additional amounts with respect to debt securities of that series; or

• in respect of a covenant or provision of the applicable W. R. Berkley indenture that cannot be modified or amended without the consent of the holder of each debt security of any series. (Section 5.13)

Under each W. R. Berkley indenture, we are required to furnish the trustee annually a statement as to performance by us of certain of our obligations under such W. R. Berkley indenture and as to any default in such performance. We are also required to deliver to the trustee, within five days after occurrence thereof, written notice of any Event of Default or any event which after notice or lapse of time or both would constitute an Event of Default. (Section 10.7)

Discharge, Defeasance and Covenant Defeasance

We may discharge certain obligations to holders of any series of debt securities that have not already been delivered to the trustee for cancellation and that either have become due and payable or will become due and payable within one year, or scheduled for redemption within one year, by depositing with the trustee, in trust, funds in U.S. dollars or in the Foreign Currency in which such debt securities are payable in an amount sufficient to pay the entire indebtedness on such debt securities with respect to principal and any premium, interest and additional amounts to the date of such deposit, if such debt securities have become due and payable, or to the maturity thereof, as the case may be. (Section 4.1)

Each W. R. Berkley indenture provides that, unless the provisions of Section 4.2 thereof are made inapplicable to debt securities of or within any series pursuant to Section 3.1 thereof, we may elect either:

• to defease and be discharged from any and all obligations with respect to such debt securities, except

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for, among other things, the obligation to pay additional amounts, if any, upon the occurrence of certain events of taxation, assessment or governmental charge with respect to payments on such debt securities and other obligations to register the transfer or exchange of such debt securities, to replace temporary or mutilated, destroyed, lost or stolen debt securities, to maintain an office or agency with respect to such debt securities and to hold moneys for payment in trust; or

• to be released from its obligations with respect to such debt securities under certain covenants as described in the related prospectus supplement, and any omission to comply with such obligations will not constitute a default or an Event of Default with respect to such debt securities.

Such defeasance or such covenant defeasance, as the case may be, will be conditioned upon the irrevocable deposit by us with the trustee, in trust, of an amount in U.S. dollars or in the Foreign Currency in which such debt securities are payable at stated maturity, or Government Obligations, or both, applicable to such debt securities which through the scheduled payment of principal and interest in accordance with their terms will provide money in an amount sufficient to pay the principal of, any premium and interest on, and any additional amounts with respect to, such debt securities on the scheduled due dates. (Section 4.2)

Such a trust may only be established if, among other things:

• the applicable defeasance or covenant defeasance does not result in a breach or violation of, or constitute a default under, the applicable W. R. Berkley indenture or any other material agreement or instrument to which we are a party or by which we are bound;

• no Event of Default or event which with notice or lapse of time or both would become an Event of Default with respect to the debt securities to be defeased will have occurred and be continuing on the date of establishment of such a trust and, with respect to defeasance only, at any time during the period ending on the 123rd day after such date; and

• we have delivered to the trustee an opinion of counsel, as specified in the applicable W. R. Berkley indenture, to the effect that the holders of such debt securities will not recognize income, gain or loss for United States Federal income tax purposes as a result of such defeasance or covenant defeasance and will be subject to United States Federal income tax on the same amounts, in the same manner and at the same times as would have been the case if such defeasance or covenant defeasance had not occurred, and such opinion of counsel, in the case of defeasance, must refer to and be based upon a letter ruling of the Internal Revenue Service received by us, a Revenue Ruling published by the Internal Revenue Service or a change in applicable United States Federal income tax law occurring after the date of the applicable W. R. Berkley indenture. (Section 4.2)

“Foreign Currency” means any currency, currency unit or composite currency, including, without limitation, the euro, issued by the government of one or more countries other than the United States of America or by any recognized confederation or association of such governments. (Section 1.1)

“Government Obligations” means debt securities which are:

(1) direct obligations of the United States of America or the government or the governments which issued the Foreign Currency in which the debt securities of a particular series are payable, for the payment of which its full faith and credit is pledged; or

(2) obligations of a Person controlled or supervised by and acting as an agency or instrumentality of the United States of America or such government or governments which issued the Foreign Currency in which the debt securities of such series are payable, the timely payment of which is unconditionally guaranteed as a full faith and credit obligation by the United States of America or such other government or governments, which, in the case of clauses (1) and (2), are not callable or redeemable at the option of the issuer or issuers thereof, and will also include a depository receipt issued by a bank or trust company as custodian with

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respect to any such Government Obligation or a specific payment of interest on or principal of or any other amount with respect to any such Government Obligation held by such custodian for the account of the holder of such depository receipt, provided that, except as required by law, such custodian is not authorized to make any deduction from the amount payable to the holder of such depository receipt from any amount received by the custodian with respect to the Government Obligation or the specific payment of interest on or principal of or any other amount with respect to the Government Obligation evidenced by such depository receipt. (Section 1.1)

If after we have deposited funds and/or Government Obligations to effect defeasance or covenant defeasance with respect to debt securities of any series:

(1) the holder of a debt security of that series is entitled to, and does, elect pursuant to Section 3.1 of the applicable W. R. Berkley indenture or the terms of such debt security to receive payment in a currency other than that in which such deposit has been made in respect of such debt security; or

(2) a Conversion Event occurs in respect of the Foreign Currency in which such deposit has been made;

then the indebtedness represented by such debt security will be deemed to have been, and will be, fully discharged and satisfied through the payment of the principal of, any premium and interest on, and any additional amounts with respect to, such debt security as such debt security becomes due out of the proceeds yielded by converting the amount or other properties so deposited in respect of such debt security into the currency in which such debt security becomes payable as a result of such election or such Conversion Event based on:

• in the case of payments made pursuant to clause (1) above, the applicable market exchange rate for such currency in effect on the second business day prior to such payment date; or

• with respect to a Conversion Event, the applicable market exchange rate for such Foreign Currency in effect, as nearly as feasible, at the time of the Conversion Event. (Section 4.2)

“Conversion Event” means the cessation of use of:

• a Foreign Currency both by the government of the country or countries which issued such Foreign Currency and for the settlement of transactions by a central bank or other public institutions of or within the international banking community; or

• any currency unit or composite currency for the purposes for which it was established.

All payments of principal of, any premium and interest on, and any additional amounts with respect to, any debt security that are payable in a Foreign Currency that ceases to be used by the government or governments of issuance will be made in U.S. dollars. (Section 1.1)

In the event we effect covenant defeasance with respect to any debt securities and such debt securities are declared due and payable because of the occurrence of any Event of Default other than an Event of Default with respect to any covenant as to which there has been covenant defeasance, the amount in such Foreign Currency in which such debt securities are payable, and Government Obligations on deposit with the trustee, will be sufficient to pay amounts due on such debt securities at the time of the stated maturity but may not be sufficient to pay amounts due on such debt securities at the time of the acceleration resulting from such Event of Default. However, we would remain liable to make payment of such amounts due at the time of acceleration.

Subordination of the Subordinated Debt Securities

The subordinated debt securities will, to the extent set forth in the subordinated indenture, be subordinate in right of payment to the prior payment in full of all Senior Indebtedness. (Section 16.1 of the subordinated indenture). In the event of:

• any insolvency or bankruptcy case or proceeding, or any receivership, liquidation, reorganization or

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other similar case or proceeding in connection therewith, relative to us or to our creditors, as such, or to our assets;

• any voluntary or involuntary liquidation, dissolution or other winding-up of ours, whether or not involving insolvency or bankruptcy; or

• any assignment for the benefit of creditors or any other marshalling of assets and liabilities of ours,

then and in any such event the holders of Senior Indebtedness will be entitled to receive payment in full of all amounts due or to become due on or in respect of all Senior Indebtedness, or provision will be made for such payment in cash, before the holders of the subordinated debt securities are entitled to receive or retain any payment on account of principal of, or any premium or interest on, or any additional amounts with respect to, subordinated debt securities, and to that end the holders of Senior Indebtedness will be entitled to receive, for application to the payment thereof, any payment or distribution of any kind or character, whether in cash, property or securities, including any such payment or distribution which may be payable or deliverable by reason of the payment of any other Indebtedness of ours being subordinated to the payment of subordinated debt securities, which may be payable or deliverable in respect of subordinated debt securities in any such case, proceeding, dissolution, liquidation or other winding-up event. (Section 16.3 of the subordinated indenture)

By reason of such subordination, in the event of our liquidation or insolvency, holders of Senior Indebtedness and holders of other obligations of ours that are not subordinated to Senior Indebtedness may recover more, ratably, than the holders of subordinated debt securities.

Subject to the payment in full of all Senior Indebtedness, the rights of the holders of subordinated debt securities will be subrogated to the rights of the holders of Senior Indebtedness to receive payments or distributions of cash, property or securities of ours applicable to such Senior Indebtedness until the principal of, any premium and interest on, and any additional amounts with respect to, subordinated debt securities have been paid in full. (Section 16.4 of the subordinated indenture)

No payment of principal, including redemption and sinking fund payments, of or any premium or interest on or any additional amounts with respect to the subordinated debt securities may be made:

• if any Senior Indebtedness of ours is not paid when due and any applicable grace period with respect to such default has ended and such default has not been cured or waived or ceased to exist; or

• if the maturity of any Senior Indebtedness of ours has been accelerated because of a default. (Section 16.2 of the subordinated indenture)

The subordinated indenture does not limit or prohibit us from incurring additional Senior Indebtedness, which may include Indebtedness that is senior to subordinated debt securities, but subordinate to our other obligations. The senior debt securities will constitute Senior Indebtedness under the subordinated indenture.

The term “Senior Indebtedness” means all Indebtedness of ours outstanding at any time, except:

• the subordinated debt securities;

• indebtedness as to which, by the terms of the instrument creating or evidencing the same, it is provided that such Indebtedness is subordinated to or ranks equally with the subordinated debt securities;

• Indebtedness of ours to an affiliate of ours;

• interest accruing after the filing of a petition initiating any bankruptcy, insolvency or other similar proceeding unless such interest is an allowed claim enforceable against us in a proceeding under federal or state bankruptcy laws; and

• trade accounts payable.

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Such Senior Indebtedness will continue to be Senior Indebtedness and be entitled to the benefits of the subordination provisions irrespective of any amendment, modification or waiver of any term of such Senior Indebtedness. (Sections 1.1 and 16.8 of the subordinated indenture)

The subordinated indenture provides that the foregoing subordination provisions, insofar as they relate to any particular issue of subordinated debt securities, may be changed prior to such issuance. Any such change would be described in the related prospectus supplement.

New York Law to Govern

The W. R. Berkley indentures and the debt securities will be governed by, and construed in accordance with, the laws of the State of New York applicable to agreements made or instruments entered into and, in each case, performed wholly in that state. (Section 1.13)

Information Concerning the Trustee

We may from time to time borrow from, maintain deposit accounts with and conduct other banking transactions with the trustee and its affiliates in the ordinary course of business. The trustee will be named in the applicable prospectus supplement.

Under each W. R. Berkley indenture, the trustee may be required to transmit annual reports to all holders regarding its eligibility and qualifications as trustee under the applicable W. R. Berkley indenture and related matters. (Section 7.3)

DESCRIPTION OF THE WARRANTS TO PURCHASE

COMMON STOCK OR PREFERRED STOCK

The following statements with respect to the common stock warrants and preferred stock warrants are summaries of the material provisions of a stock warrant agreement to be entered into by us and a stock warrant agent to be selected at the time of issue. The stock warrant agreement may include or incorporate by reference standard warrant provisions substantially in the forms of the Common Stock Warrant Agreement and the Preferred Stock Warrant Agreement filed as exhibits to the registration statement of which this prospectus forms a part.

General

The stock warrants, evidenced by stock warrant certificates, may be issued under the stock warrant agreement independently or together with any other securities offered by any prospectus supplement and may be attached to or separate from such other offered securities. If stock warrants are offered, the related prospectus supplement will describe the designation and terms of the stock warrants, including, without limitation, the following:

• the offering price, if any;

• the designation and terms of the common stock or preferred stock purchasable upon exercise of the stock warrants;

• if applicable, the date on and after which the stock warrants and the related offered securities will be separately transferable;

• the number of shares of common stock or preferred stock purchasable upon exercise of one stock warrant and the initial price at which such shares may be purchased upon exercise;

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• the date on which the right to exercise the stock warrants shall commence and the date on which such right shall expire;

• a discussion of certain United States Federal income tax considerations;

• the call provisions, if any;

• the currency, currencies or currency units in which the offering price, if any, and exercise price are payable;

• the anti-dilution provisions of the stock warrants; and

• any other terms of the stock warrants.

The shares of common stock or preferred stock issuable upon exercise of the stock warrants will, when issued in accordance with the stock warrant agreement, be fully paid and non-assessable.

Exercise of Stock Warrants

Stock warrants may be exercised by surrendering to the stock warrant agent the stock warrant certificate with the form of election to purchase on the reverse thereof duly completed and signed by the warrantholder, or its duly authorized agent, indicating the warrantholder’s election to exercise all or a portion of the stock warrants evidenced by the certificate. The signature must be guaranteed by a bank or trust company, by a broker or dealer which is a member of the Financial Industry Regulatory Authority (“FINRA”) or by a member of a national securities exchange. Surrendered stock warrant certificates shall be accompanied by payment of the aggregate exercise price of the stock warrants to be exercised, as set forth in the related prospectus supplement, in lawful money of the United States, unless otherwise provided in the related prospectus supplement. Upon receipt thereof by the stock warrant agent, the stock warrant agent will requisition from the transfer agent for the common stock or the preferred stock, as the case may be, for issuance and delivery to or upon the written order of the exercising warrantholder, a certificate representing the number of shares of common stock or preferred stock purchased. If less than all of the stock warrants evidenced by any stock warrant certificate are exercised, the stock warrant agent shall deliver to the exercising warrantholder a new stock warrant certificate representing the unexercised stock warrants.

Anti-dilution and Other Provisions

The exercise price payable and the number of shares of common stock or preferred stock purchasable upon the exercise of each stock warrant and the number of stock warrants outstanding will be subject to adjustment in certain events, including the issuance of a stock dividend to holders of common stock or preferred stock, respectively, or a combination, subdivision or reclassification of common stock or preferred stock, respectively. In lieu of adjusting the number of shares of common stock or preferred stock purchasable upon exercise of each stock warrant, we may elect to adjust the number of stock warrants. No adjustment in the number of shares purchasable upon exercise of the stock warrants will be required until cumulative adjustments require an adjustment of at least 1% thereof. We may, at our option, reduce the exercise price at any time. No fractional shares will be issued upon exercise of stock warrants, but we will pay the cash value of any fractional shares otherwise issuable. Notwithstanding the foregoing, in case of our consolidation, merger, or sale or conveyance of our property as an entirety or substantially as an entirety, the holder of each outstanding stock warrant shall have the right to the kind and amount of shares of stock and other securities and property, including cash, receivable by a holder of the number of shares of common stock or preferred stock into which such stock warrants were exercisable immediately prior thereto.

No Rights as Stockholders

Holders of stock warrants will not be entitled, by virtue of being such holders, to vote, to consent, to receive dividends, to receive notice as stockholders with respect to any meeting of stockholders for the election of our directors or any other matter, or to exercise any rights whatsoever as our stockholders.

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DESCRIPTION OF THE WARRANTS TO PURCHASE DEBT SECURITIES

The following statements with respect to the debt warrants are summaries of the material provisions of a debt warrant agreement to be entered into by us and a debt warrant agent to be selected at the time of issue. The debt warrant agreement may include or incorporate by reference standard warrant provisions substantially in the form of the Debt Warrant Agreement filed as an exhibit to the registration statement of which this prospectus forms a part.

General

The debt warrants, evidenced by debt warrant certificates, may be issued under the debt warrant agreement independently or together with any other securities offered by any prospectus supplement and may be attached to or separate from such other offered securities. If debt warrants are offered, the related prospectus supplement will describe the designation and terms of the debt warrants, including without limitation the following:

• the offering price, if any;

• the designation, aggregate principal amount and terms of the debt securities purchasable upon exercise of the debt warrants;

• if applicable, the date on and after which the debt warrants and the related offered securities will be separately transferable;

• the principal amount of debt securities purchasable upon exercise of one debt warrant and the price at which such principal amount of debt securities may be purchased upon exercise;

• the date on which the right to exercise the debt warrants shall commence and the date on which such right shall expire;

• a discussion of certain United States Federal income tax considerations;

• whether the warrants represented by the debt warrant certificates will be issued in registered or bearer form;

• the currency, currencies or currency units in which the offering price, if any, and exercise price are payable;

• the anti-dilution provisions of the debt warrants; and

• any other terms of the debt warrants.

Warrantholders will not have any of the rights of holders of debt securities, including the right to receive the payment of principal of, any premium or interest on, or any additional amounts with respect to, the debt securities or to enforce any of the covenants of the debt securities or the applicable W. R. Berkley indenture except as otherwise provided in the applicable W. R. Berkley indenture.

Exercise of Debt Warrants

Debt warrants may be exercised by surrendering the debt warrant certificate at the office of the debt warrant agent, with the form of election to purchase on the reverse side of the debt warrant certificate properly completed and executed, and by payment in full of the exercise price, as set forth in the related prospectus supplement. The signature must be guaranteed by a bank or trust company, by a broker or dealer which is a member of FINRA or by a member of a national securities exchange. Upon the exercise of debt warrants, we will issue the debt securities in authorized denominations in accordance with the instructions of the exercising warrantholder. If less than all of the debt warrants evidenced by the debt warrant certificate are exercised, a new debt warrant certificate will be issued for the remaining number of debt warrants.

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DESCRIPTION OF STOCK PURCHASE CONTRACTS

AND STOCK PURCHASE UNITS

We may issue stock purchase contracts, representing contracts obligating holders to purchase from us, and obligating us to sell to the holders, a specified number of shares of common stock or preferred stock at a future date or dates. The price per share may be fixed at the time the stock purchase contracts are issued or may be determined by reference to a specific formula set forth in the stock purchase contracts. The stock purchase contracts may be issued separately or as a part of stock purchase units consisting of a stock purchase contract and, as security for the holder’s obligations to purchase the shares under the stock purchase contracts, either:

• our senior debt securities or our subordinated debt securities,

• our common stock;

• our preferred stock;

• other stock purchase contracts;

• depositary shares representing fractional interests in debt securities or shares of common stock or preferred stock; or

• preferred securities or debt obligations of third parties, including U.S. Treasury securities.

The stock purchase contracts may require us to make periodic payments to the holders of the stock purchase units or vice versa, and such payments may be unsecured or prefunded on some basis. The stock purchase contracts may require holders to secure their obligations in a specified manner and in certain circumstances we may deliver newly issued prepaid stock purchase contracts upon release to a holder of any collateral securing such holder’s obligations under the original stock purchase contract.

The applicable prospectus supplement will describe the terms of any stock purchase contracts or stock purchase units and, if applicable, prepaid stock purchase contracts. The description in the prospectus supplement will not purport to be complete and will be qualified in its entirety by reference to:

• the stock purchase contracts;

• the collateral arrangements and depositary arrangements, if applicable, relating to such stock purchase contracts or stock purchase units; and

• if applicable, the prepaid stock purchase contracts and the document pursuant to which such prepaid stock purchase contracts will be issued.

PLAN OF DISTRIBUTION

We may sell offered securities in any one or more of the following ways from time to time: through agents; to or through underwriters; through dealers; or directly to purchasers. The prospectus supplement with respect to the offered securities will set forth the terms of the offering of the offered securities, including the name or names of any underwriters, dealers or agents; the purchase price of the offered securities and the proceeds to us from such sale; any underwriting discounts and commissions or agency fees and other items constituting underwriters’ or agents’ compensation; any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers and any securities exchange on which such offered securities may be listed. Any initial public offering price, discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

The distribution of the offered securities may be effected from time to time in one or more transactions at a fixed price or prices, which may be changed, at market prices prevailing at the time of sale, at prices related to such prevailing market prices or at negotiated prices.

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Offers to purchase offered securities may be solicited by agents designated by us from time to time. Any such agent involved in the offer or sale of the offered securities in respect of which this prospectus is delivered will be named, and any commissions payable by us to such agent will be set forth, in the applicable prospectus supplement. Unless otherwise indicated in such prospectus supplement, any such agent will be acting on a reasonable best efforts basis for the period of its appointment. Any such agent may be deemed to be an underwriter, as that term is defined in the Securities Act, of the offered securities so offered and sold.

If offered securities are sold by means of an underwritten offering, we will execute an underwriting agreement with an underwriter or underwriters, and the names of the specific managing underwriter or underwriters, as well as any other underwriters, and the terms of the transaction, including commissions, discounts and any other compensation of the underwriters and dealers, if any, will be set forth in the prospectus supplement that will be used by the underwriters to make resales of the offered securities. If underwriters are utilized in the sale of the offered securities, the offered securities will be acquired by the underwriters for their own account and may be resold from time to time in one or more transactions, including negotiated transactions, at fixed public offering prices or at varying prices determined by the underwriters at the time of sale. Our offered securities may be offered to the public either through underwriting syndicates represented by managing underwriters or directly by the managing underwriters. If any underwriter or underwriters are utilized in the sale of the offered securities, unless otherwise indicated in the prospectus supplement, the underwriting agreement will provide that the obligations of the underwriters are subject to certain conditions precedent and that the underwriters with respect to a sale of offered securities will be obligated to purchase all such offered securities of a series if any are purchased.

We may grant to the underwriters options to purchase additional offered securities, to cover over-allotments, if any, at the public offering price, with additional underwriting discounts or commissions, as may be set forth in the prospectus supplement relating thereto. If we grant any over-allotment option, the terms of such over-allotment option will be set forth in the prospectus supplement relating to such offered securities.

If a dealer is utilized in the sales of offered securities in respect of which this prospectus is delivered, we will sell such offered securities to the dealer as principal. The dealer may then resell such offered securities to the public at varying prices to be determined by such dealer at the time of resale. Any such dealer may be deemed to be an underwriter, as such term is defined in the Securities Act, of the offered securities so offered and sold. The name of the dealer and the terms of the transaction will be set forth in the related prospectus supplement.

Offers to purchase offered securities may be solicited directly by us and the sale thereof may be made by us directly to institutional investors or others, who may be deemed to be underwriters within the meaning of the Securities Act with respect to any resale thereof. The terms of any such sales will be described in the related prospectus supplement.

Offered securities may also be offered and sold, if so indicated in the applicable prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more firms, acting as principals for their own accounts or our as agents. Any such remarketing firm will be identified and the terms of its agreements, if any, with us and its compensation will be described in the applicable prospectus supplement. Remarketing firms may be deemed to be underwriters, as such term is defined in the Securities Act, in connection with the offered securities remarketed thereby.

Agents, underwriters, dealers and remarketing firms may be entitled under relevant agreements entered into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act that may arise from any untrue statement or alleged untrue statement of a material fact or any omission or alleged omission to state a material fact in this prospectus, any supplement or amendment hereto, or in the registration statement of which this prospectus forms a part, or to contribution with respect to payments which the agents, underwriters or dealers may be required to make.

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If so indicated in the prospectus supplement, we will authorize underwriters or other persons acting as our agents to solicit offers by certain institutions to purchase offered securities from us at the public offering price, pursuant to contracts providing for payments and delivery on a future date. Institutions with which such contracts may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and others, but in all cases such institutions must be approved by us. The obligations of any purchaser under any such contract will be subject to the condition that the purchase of the offered securities shall not at the time of delivery be prohibited under the laws of the jurisdiction to which such purchaser is subject. The underwriters and such other agents will not have any responsibility in respect of the validity or performance of such contracts. Disclosure in the prospectus supplement of our use of delayed delivery contracts will include the commission that underwriters and agents soliciting purchases of the securities under delayed contracts will be entitled to receive in addition to the date when we will demand payment and delivery of the securities under the delayed delivery contracts. These delayed delivery contracts will be subject only to the conditions described in the prospectus supplement.

Each series of offered securities will be a new issue and, other than the shares of common stock that are listed on the New York Stock Exchange, will have no established trading market. We may elect to list any series of offered securities on an exchange, and in the case of common stock, on any additional exchange, but, unless otherwise specified in the applicable prospectus supplement, we shall not be obligated to do so. We cannot predict the liquidity of the trading market for any of the offered securities.

Underwriters, dealers, agents and remarketing firms, or their affiliates, may be customers of, engage in transactions with, or perform services for, us and our subsidiaries in the ordinary course of business.

LEGAL MATTERS

Unless otherwise stated in the applicable prospectus supplement, the validity of any securities offered by us in the applicable prospectus supplement will be passed upon for us by Willkie Farr & Gallagher LLP, New York, New York. The validity of any securities offered in the applicable prospectus supplement will be passed upon for any underwriters or agents by counsel to be named in the applicable prospectus supplement. As of November 5, 2020, Jack H. Nusbaum, Senior Partner of Willkie Farr & Gallagher LLP and a member of our board of directors, beneficially owned 149,799 shares of our common stock.

EXPERTS

The consolidated financial statements of W. R. Berkley Corporation and subsidiaries as of December 31, 2019 and 2018, and for each of the years in the three-year period ended December 31, 2019, and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2019, have been incorporated by reference in this prospectus by reference to our Annual Report on Form 10-K for the year ended December 31, 2019 in reliance upon the reports of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing. The audit report covering the December 31, 2019 financial statements refers to a change in method of accounting for equity investments measured at fair value with changes in the fair value recognized through net income (other than those accounted for under equity method of accounting or those that result in consolidation of the investee) effective January 1, 2018 due to the adoption of ASU 2016-01, Financial Instruments.

WHERE YOU CAN FIND MORE INFORMATION

We have filed with the Commission a registration statement on Form S-3 under the Securities Act, relating to our common stock and other securities. This prospectus is a part of such registration statement, but such registration statement also contains additional information and exhibits.

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We are subject to the informational requirements of the Exchange Act. Accordingly, we file annual, quarterly and current reports, proxy statements and other information with the Commission. Our public filings are available from the Commission’s website at http://www.sec.gov. Information about us is also available on our web site at http://www.wrberkley.com. Information on our web site is not a part of this prospectus.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The Commission allows us to “incorporate by reference” the information we file with it, which means that we can disclose important information to you by referring to those documents. The information incorporated by reference is an important part of this prospectus. Any statement contained in a document that is incorporated by reference in this prospectus is automatically updated and superseded if information contained in this prospectus, or information that we later file with the Commission, modifies or replaces this information. We incorporate by reference the following documents:

• Our Annual Report on Form 10-K for the year ended December 31, 2019;

• Our Quarterly Reports on Form 10-Q for the quarterly periods ended March 31, 2020, June  30, 2020 and September 30, 2020;

• Our Current Report on Form 8-K, dated May  5, 2020, May  12, 2020, May  27, 2020, June  12, 2020, September  1, 2020, September  9, 2020, September  17, 2020 and September 21, 2020;

• Our Definitive Proxy Statement on Schedule 14A (solely to the extent incorporated by reference into our Annual Report on Form 10-K for the year ended December 31, 2019); and

• The descriptions of our common stock set forth in our registration statement on Form 8-A/A filed with the Commission on May 1, 2001, including any further amendments or reports for the purposes of updating such descriptions.

All documents we subsequently file pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, prior to the termination of this offering, shall also be deemed to be incorporated by reference into this prospectus.

To receive a free copy of any of the documents incorporated by reference in this prospectus, other than any exhibits, unless the exhibits are specifically incorporated by reference into this prospectus, call us at (203) 629-3000 or write us at the following address: W. R. Berkley Corporation, 475 Steamboat Road, Greenwich, Connecticut 06830, Attention: Philip S. Welt, Esq., Executive Vice President, General Counsel & Secretary.

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W. R. Berkley Corporation