Exhibit 99.1

ALLEGHANY CORPORATION
7 TIMES SQUARE TOWER, 17TH FLOOR
NEW YORK, NY 10036

                                                              Contact: R.M. Hart
                                                              (212) 752-1356

                                                           FOR IMMEDIATE RELEASE

              ALLEGHANY ANNOUNCES PRICING OF MANDATORY CONVERTIBLE
                            PREFERRED STOCK OFFERING

          NEW YORK, NY, JUNE 20, 2006 - Alleghany Corporation ("Alleghany")
(NYSE-Y) today announced that it has set the price for the public offering of
985,000 shares of its 5.75% mandatory convertible preferred stock due June 15,
2009 at $264.60 per share. The mandatory convertible preferred stock will have a
dividend yield of 5.75% and a conversion premium of 18% above the public
offering price. The underwriters have an option to purchase from Alleghany up to
an additional 147,000 shares of mandatory convertible preferred stock to cover
over-allotments, if any.

          The estimated net proceeds to Alleghany from the mandatory convertible
preferred stock offering (assuming the exercise in full of the underwriters'
over-allotment option) is expected to be approximately $290 million. Alleghany
currently intends to use the net proceeds to make contributions to the capital
and surplus of its insurance operating units, including contributions to benefit
the commercial property operations of its subsidiary RSUI Group, Inc., and for
general corporate purposes.

          Merrill Lynch & Co. is acting as the sole book-running manager and
Wachovia Capital Markets, LLC, Dowling & Partners Securities, LLC and Janney
Montgomery Scott LLC are acting as co-managers for the mandatory convertible
preferred stock offering.

          The mandatory convertible preferred stock will be sold pursuant to an
effective shelf registration statement previously filed with the Securities and
Exchange Commission (the "SEC"). A prospectus supplement relating to the
offering of the mandatory convertible preferred stock has also been filed with
the SEC. Copies of the prospectus supplement and the accompanying base
prospectus relating to the offering can be obtained from Merrill Lynch & Co., 4
World Financial Center, New York, New York 10080; Phone 212-449-1000.

          This press release shall not constitute an offer to sell or the
solicitation of an offer to buy, nor shall there be any sale of the mandatory
convertible preferred stock in any state or jurisdiction in which such offer,
solicitation or sale would be unlawful prior to registration or qualification
under the securities laws of any such state or jurisdiction. Any offering of
mandatory convertible preferred stock is being made only by means of a



written prospectus meeting the requirements of Section 10 of the Securities Act
of 1933, as amended.

          Alleghany is engaged through its subsidiary Alleghany Insurance
Holdings LLC (consisting of RSUI Group, Inc., Capitol Transamerica Corporation
and Darwin Professional Underwriters, Inc.) in the property and casualty
insurance business.

          This press release contains forward-looking statements with respect to
the anticipated effects of the transaction. Actual results of the transaction
could be significantly different. Factors that could affect results include
those set forth in filings made by Alleghany with the SEC. Although
forward-looking statements help to provide complete information about future
prospects, readers should keep in mind that forward-looking statements are much
less reliable than historical information.

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