[Letterhead of Appleby Spurling & Kempe]



                                                                     Exhibit 5.1

                                                                14 November 2003

Aspen Insurance Holdings Limited
Victoria Hall
11 Victoria Street
Hamilton HM 11
Bermuda

Dear Sirs

ASPEN INSURANCE HOLDINGS LIMITED (THE "COMPANY") - REGISTRATION STATEMENT ON
FORM F-1

We have acted as Bermuda counsel to the Company, and this opinion as to Bermuda
law is addressed to you in connection with the filing by the Company with the
United States Securities and Exchange Commission under the Securities Act of
1933, as amended (the "Securities Act") of a Registration Statement on Form F-1
(No. 333-110435 filed 12 November 2003) and related documents (the "Registration
Statement") in relation to the Company issuing up to 10,952,600 ordinary shares
(including over allotments) of the Company, US 0.15144558 cents par value per
share (the "Shares").

For the purposes of this opinion we have examined and relied upon the documents
listed, and in some cases defined, in the Schedule to this opinion (the
"Documents").

Unless otherwise defined herein or in the Schedule to this opinion, terms
defined in the Registration Statement have the same meanings when used in this
opinion.

ASSUMPTIONS

In stating our opinion we have assumed:

(a)  the authenticity, accuracy and completeness of all Documents submitted to
     us as originals and the conformity to authentic original Documents of all
     Documents submitted to us as certified, conformed, notarised, faxed or
     photostatic copies:



(b)  that each of the Documents which was received by electronic means is
     complete, intact and in conformity with the transmission as sent;

(c)  the genuineness of all signatures on the Documents;

(d)  the authority, capacity and power of each of the persons signing the
     Documents which we have reviewed (other than the Company or its Directors
     or Officers);

(e)  that any statements of fact or law, other than as to Bermuda law, made in
     any of the Documents are true, accurate and complete;

(f)  that the records which were the subject to the Company Search were complete
     and accurate at the time of such search and disclosed all information which
     is material for the purposes of this opinion and such information has not
     since the date of the Company Search been materially altered;

(g)  that the records which were the subject of the Litigation Search were
     complete and accurate at the time of such search and disclosed all
     information which is material for the purposes of this opinion and such
     information has not since the date of the Litigation Search been materially
     altered;

(h)  that there are no provisions of the laws or regulations of any jurisdiction
     other than Bermuda which would be contravened by the issue of the Shares or
     which would have any implication in relation to the opinions expressed
     herein in that, in so far as any obligation to be performed or action to be
     taken as described in the Registration Statement is required to be
     performed or taken in any jurisdiction outside Bermuda, the performance of
     such obligation or the taking of such action will constitute a valid and
     binding obligation of each of the parties thereto under the laws of that
     jurisdiction and will not be illegal by virtue of the laws of that
     jurisdiction;

(i)  that the Resolutions are in full force and effect, have not been rescinded,
     either in whole or in part, and accurately record the resolutions passed by
     the Board of Directors or Shareholders of the Company in meetings which
     were duly convened and, in each case, at which a duly constituted quorum
     was present and voting throughout; and

(j)  that there is no matter affecting the authority of the Directors not
     disclosed by the Constitutional Documents, the Company Search, the
     Litigation Search, or the Resolutions, which would have any adverse
     implication in relation to the opinions expressed herein.





OPINION

Based upon and subject to the foregoing and subject to the reservations set out
below and to any matters not disclosed to us, we are of the opinion that:

(1)  The Company is an exempted company validly organised and existing and in
     good standing under the laws of Bermuda.

(2)  All necessary corporate action required to be taken by the Company in
     connection with the issue by the Company of the Shares pursuant to Bermuda
     law has been taken by or on behalf of the Company, and all necessary
     approvals of Governmental authorities in Bermuda have been duly obtained
     for the issue by the Company of the Shares.

(3)  When issued pursuant to the Resolutions and delivered against payment
     therefore in the circumstances referred to or summarised in the
     Registration Statement, the Shares will be validly issued, fully paid and
     non-assessable shares in the capital of the Company.

(4)  There are no taxes, duties or other charges payable to or chargeable by the
     Government of Bermuda, or any authority or agency thereof in respect of the
     issue of the Shares.

RESERVATIONS

We have the following reservations:

(a)  We express no opinion as to any law other than Bermuda law and none of the
     opinions expressed herein relates to compliance with or matters governed by
     the laws of any jurisdiction except Bermuda. This opinion is limited to
     Bermuda law as applied by the courts of Bermuda at the date hereof.

(b)  In paragraph (1) above, the term "good standing" means only that the
     Company has received a Certificate of Compliance from the Registrar of
     Companies in Hamilton Bermuda which confirms that the Company has neither
     failed to make any filing with any Bermuda governmental authority nor to
     pay any Bermuda government fee or tax, which might make it liable to be
     struck off the Registrar of Companies and thereby cease to exist under the
     laws of Bermuda.

(c)  Any reference in this opinion to shares being "non-assessable" shall mean,
     in relation to fully paid shares of the Company and subject to any contrary
     provision in any agreement in writing between the Company and the holder of
     the shares, that no shareholder shall be bound by an alteration to the
     Memorandum of Association or Bye-laws of the Company after the date on
     which he became a shareholder, if and so far as the alteration requires him
     to take, or subscribe for additional shares, or in any way increases his
     liability to contribute to the share capital of, or otherwise to pay money
     to, the Company.

(d)  Searches of the Register of Companies at the office of the Registrar of
     Companies and of the Supreme Court Causes Book at the Registry of the
     Supreme Court are not conclusive and it should be noted that the Register
     of Companies and the Supreme Court Causes Book do not reveal:



     (i)   details of matters which have been lodged for filing or registration
           which as a matter of best practice of the Registrar of Companies or
           the Registry of the Supreme Court would have or should have been
           disclosed on the public file, the Causes Book or the Judgment Book,
           as the case may be, but for whatever reason have not actually been
           filed or registered or are not disclosed or which, notwithstanding
           filing or registration, at the date and time the search is concluded
           are for whatever reason not disclosed or do not appear on the public
           file, the Causes Book or Judgment Book;

     (ii)  details of matters which should have been lodged for filing or
           registration at the Registrar of Companies or the Registry of the
           Supreme Court but have not been lodged for filing or registration at
           the date the search is concluded;

     (iii) whether an application to the Supreme Court for a winding-up petition
           or for the appointment of a receiver or manager has been prepared but
           not yet been presented or has been presented but does not appear in
           the Causes Book at the date and time the search is concluded;

     (iv)  whether any arbitration or administrative proceedings are pending or
           whether any proceedings are threatened, or whether any arbitrator has
           been appointed; or

     (v)   whether a receiver or manager has been appointed privately pursuant
           to the provisions of a debenture or other security, unless notice of
           the fact has been entered in the Register of Charges in accordance
           with the provisions of the Act.

Furthermore, in the absence of a statutorily defined system for the registration
of charges created by companies incorporated outside Bermuda ("overseas
companies") over their assets located in Bermuda, it is not possible to
determine definitively from searches of the Register of Charges maintained by
the Registrar of Companies in respect of such overseas companies what charges
have been registered over any of their assets located in Bermuda or whether any
one charge has priority over any other charge over such assets.

(e)  In order to issue this opinion we have carried out the Company Search as
     referred to in the Schedule to this opinion and have not enquired as to
     whether there has been any change since the date of such search.

(f)  In order to issue this opinion we have carried out the Litigation Search as
     referred to in the Schedule to this opinion and have not enquired as to
     whether there has been any change since the date of such search.

(g)  Where an obligation is to be performed in a jurisdiction other than
     Bermuda, the courts of Bermuda may refuse to enforce it to the extent that
     such performance would be illegal under the laws of, or contrary to public
     policy of, such other jurisdiction.

DISCLOSURE

This opinion is addressed to you in connection with the filing by the Company of
the Registration Statement with the United States Securities and Exchange
Commission. We



consent to the inclusion of this opinion as Exhibit 5.1 to the Registration
Statement. As Bermuda attorneys, however, we are not qualified to opine on
matters of law of any jurisdiction other than Bermuda, accordingly we do not
admit to being an expert within the meaning of the Securities Act.

Further, this opinion speaks as of its date and is strictly limited to the
matters stated herein and we assume no obligation to review or update this
opinion if applicable law or the existing facts or circumstances should change.

This opinion is governed by and is to be construed in accordance with Bermuda
law. It is given on the basis that it will not give rise to any legal
proceedings with respect thereto in any jurisdiction other than Bermuda.

Yours faithfully,



/s/ Appleby Spurling & Kempe
    ------------------------




                                    SCHEDULE

1.   The entries and filings shown in respect of the Company on the file of the
     Company maintained in the Register of Companies at the office of the
     Registrar of Companies in Hamilton, Bermuda, as revealed by a search on 13
     November, 2003 (the "Company Search").

2.   The entries and filings shown in respect of the Company in the Supreme
     Court Causes Book maintained at the Registry of the Supreme Court in
     Hamilton, Bermuda, as revealed by a search on 13 November, 2003 in respect
     of the Company (the "Litigation Search").

3.   Certified copies of the Memorandum of Association, Certificate of Deposit
     of Memorandum of Increase of Share Capital and Certificate of Registration
     of Alteration of Denomination of Capital.

4.   A certified copy of the Interim Bye-Laws adopted 20 August 2003 and a
     certified copy of the IPO Bye-laws adopted (with effect from completion of
     the initial public offering of the Shares) and approved 22 September, 2003
     of the Company (the Memorandum of Association, Certificate of Deposit of
     Memorandum of Increase of Share Capital, Certificate of Registration of
     Alteration of Denomination of Capital and Bye-Laws are collectively
     referred to as the "Constitutional Documents").

5.   A certified copy of the "Tax Assurance", dated 20 June, 2002, issued by the
     Registrar of Companies for the Minister of Finance in relation to the
     Company.

6.   Certified copy of (i) the Minutes of the Meeting of the Board of Directors
     of Aspen Insurance Holdings Limited held on 9 April 2003; (ii) the Annual
     General Meeting and Special General Meeting of Aspen Insurance Holdings
     Limited both held 22 September 2003, (the "Resolutions").

7.   A copy of the permission dated 13 November, 2003, respectively, given by
     the Bermuda Monetary Authority in relation to the Company.

8.   A Certificate of Compliance, dated 13 November, 2003 issued by the Ministry
     of Finance in respect of the Company.

9.   A copy of the Registration Statement.