<PAGE>

     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 8, 2005

                                                           REGISTRATION NO. 333-
================================================================================
                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                          ----------------------------
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                        ---------------------------------

                              ALLEGHANY CORPORATION
             (Exact name of registrant as specified in its charter)

       DELAWARE                                       51-0283071
(STATE OF INCORPORATION)                (I.R.S. EMPLOYER IDENTIFICATION NUMBER)

          7 TIMES SQUARE TOWER
          NEW YORK, NEW YORK                                 10036
(ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                   (ZIP CODE)

     ALLEGHANY CORPORATION AMENDED AND RESTATED DIRECTORS' STOCK OPTION PLAN
             ALLEGHANY CORPORATION 2000 DIRECTORS' STOCK OPTION PLAN
                ALLEGHANY CORPORATION 2005 DIRECTORS' STOCK PLAN
          ALLEGHANY CORPORATION SUBSIDIARY DIRECTORS' STOCK OPTION PLAN
                            (FULL TITLE OF THE PLANS)

                                 ROBERT M. HART
              SENIOR VICE PRESIDENT, GENERAL COUNSEL AND SECRETARY
                              ALLEGHANY CORPORATION
                              7 TIMES SQUARE TOWER
                            NEW YORK, NEW YORK 10036
                                 (212) 752-1356
            (NAME, ADDRESS AND TELEPHONE NUMBER OF AGENT FOR SERVICE)

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
                                                                                    PROPOSED MAXIMUM
TITLE OF SECURITIES TO BE   AMOUNT TO BE REGISTERED       PROPOSED MAXIMUM          AGGREGATE OFFERING            AMOUNT OF
        REGISTERED                     (1)             OFFERING PRICE PER SHARE          PRICE )               REGISTRATION FEE
-------------------------   -----------------------    ------------------------     ------------------         ----------------
<S>                         <C>                        <C>                          <C>                        <C>
Common Stock, par value        28,487 shares (2)                     (6)            $ 6,436,627.50 (7)            $  758
    $1.00 per share
Common Stock, par value        35,000 shares (3)                     (6)            $ 6,939,012.50 (7)            $  817
    $1.00 per share
Common Stock, par value        50,000 shares (4)               307.27(8)            $15,363,500.00 (8)            $1,809
    $1.00 per share
Common Stock, par value         7,000 shares (5)                     (6)            $ 1,467,281.40 (7)            $  173
    $1.00 per share
</TABLE>

(1)   Pursuant to Rule 416(a) under the Securities Act of 1933, as amended, this
      Registration Statement also covers any additional shares of Common Stock
      which become issuable pursuant to the provisions of the plans listed above
      by reason of antidilution and other adjustments.

(2)   Up to 28,487 shares of Common Stock may be issued under the Alleghany
      Corporation Amended and Restated Directors' Stock Option Plan.

(3)   Up to 35,000 shares of Common Stock may be issued under the Alleghany
      Corporation 2000 Directors' Stock Option Plan.

(4)   Up to 50,000 shares of Common Stock may be issued under the Alleghany
      Corporation 2005 Directors' Stock Plan.

(5)   Up to 7,000 shares of Common Stock may be issued under the Alleghany
      Corporation Subsidiary Directors' Stock Option Plan.

(6)   The offering price per share varied from option grant to option grant.

(7)   Pursuant to Rule 457(h) of the Securities Act of 1933, as amended, solely
      for the purpose of calculating the registration fee, these amounts were
      estimated on the basis of the prices at which the options under the plans
      may be exercised.

(8)   Pursuant to Rule 457(h) of the Securities Act of 1933, as amended, solely
      for the purpose of calculating the registration fee, these amounts were
      estimated on the basis of the average of the high and low sales prices of
      the Common Stock as reported on the New York Stock Exchange on August 4,
      2005.

================================================================================
<PAGE>

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

            The document(s) containing the information specified by Part I of
this Form S-8 registration statement (this "Registration Statement") will be
sent or given to participants in the plans listed on the cover of this
Registration Statement (the "Plans") as specified in Rule 428(b)(1) promulgated
by the Securities and Exchange Commission (the "Commission") under the
Securities Act of 1933, as amended (the "Securities Act"). Such document(s) are
not being filed with the Commission either as part of this Registration
Statement or as prospectuses or prospectus supplements pursuant to Rule 424 but
taken together, along with the documents incorporated by reference in this
Registration Statement pursuant to Item 3 of Part II hereof, constitute a
prospectus that meets the requirements of Section 10(a) of the Securities Act.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

            The following documents filed with the Commission by Alleghany
Corporation (the "Company") are incorporated herein by reference and made a part
hereof:

      (a)   The Company's Annual Report on Form 10-K for the fiscal year ended
            December 31, 2004;

      (b)(i)The Company's Quarterly Report on Form 10-Q for the quarter ended
            March 31, 2005;

        (ii)The Company's Current Reports on Form 8-K filed on January 5,
            February 8, March 10, April 8, April 21, April 22, April 28,
            May 23, July 20 and July 25, 2005; and

      (c)   The description of the Company's Common Stock contained in the
            Company's Registration Statement on Form 10 filed pursuant to
            Section 12 of the Securities Exchange Act of 1934, as amended (the
            "Exchange Act"), which incorporates by reference certain portions of
            the Company's Proxy Statement dated November 26, 1986 relating to
            its Special Meeting of Stockholders held on December 19, 1986; such
            description is qualified in its entirety by reference to (i) the
            Company's Restated Certificate of Incorporation, as amended, and
            (ii) the Company's By-Laws, as amended, incorporated by reference as
            Exhibits 3.1 and 3.2, respectively, in this Registration Statement,
            and any amendment or report filed for the purpose of updating that
            description.

                                       2

<PAGE>

            All documents subsequently filed by the Company pursuant to Sections
13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment which indicates that all securities offered hereunder
have been sold or which deregisters all securities then remaining unsold
hereunder, shall be deemed to be incorporated by reference herein and to be a
part hereof from the date of filing of such documents. Any statement contained
in a document incorporated or deemed to be incorporated by reference herein
shall be deemed to be modified or superseded for purposes of this Registration
Statement to the extent that a statement contained herein (or in any other
subsequently filed document that also is or is deemed to be incorporated by
reference herein or therein) modifies or supersedes such statement. Any
statement so modified or superseded shall not be deemed, except as so modified
or superseded, to constitute a part of this Registration Statement.

            The consolidated financial statements and financial statement
schedules of the Company and its subsidiaries included in or incorporated by
reference in the Company's Annual Report on Form 10-K for the fiscal year ended
December 31, 2004 have been incorporated herein by reference in reliance upon
the reports, also incorporated herein by reference, of KPMG LLP, independent
registered public accounting firm, given on its authority as experts in
accounting and auditing.

Item 4. Description of Securities.

            Not applicable.

Item 5. Interests of Named Experts and Counsel.

            Not applicable.

Item 6. Indemnification of Directors and Officers.

            The Company is a Delaware corporation. Reference is made to Section
145 of the Delaware General Corporation Law as to indemnification by the Company
of its officers and directors. The general effect of such law is to empower a
corporation to indemnify any of its officers and directors against certain
expenses (including attorneys' fees), judgments, fines and amounts paid in
settlement actually and reasonably incurred by the person to be indemnified in
connection with certain actions, suits or proceedings (threatened, pending or
completed) if the person to be indemnified acted in good faith and in a manner
he reasonably believed to be in, or not opposed to, the best interests of the
corporation and, with respect to any criminal action or proceeding, had no
reasonable cause to believe his conduct was unlawful.

            Article Tenth of the Company's Restated Certificate of
Incorporation, as amended (which Restated Certificate of Incorporation is
incorporated herein by reference as Exhibit 3.1 in this Registration Statement),
provides for the indemnification of the Company's officers and directors in
accordance with the Delaware General Corporation Law, and includes, as permitted
by the Delaware General Corporation Law, certain limitations on the potential
personal liability of members of the Company's Board of

                                       3

<PAGE>

Directors for monetary damages as a result of actions taken in their capacity as
Board members.

            The directors and officers of the Company are covered by insurance
policies indemnifying them against certain liabilities arising under the
Securities Act, which might be incurred by them in such capacities.

Item 7. Exemption from Registration Claimed.

            Not applicable.

Item 8. Exhibits.

            The following are filed as exhibits hereto.
<TABLE>
<CAPTION>
Exhibit Number                         Description
--------------          --------------------------------------------
<S>                     <C>
    3.1                 The Company's Restated Certificate of
                        Incorporation, as amended by Amendment
                        accepted and received for filing by the
                        Secretary of State of the State of Delaware
                        on June 23, 1988, filed as Exhibit 20 to the
                        Company's Quarterly Report on Form 10-Q for
                        the quarter ended June 30, 1988, is
                        incorporated herein by reference.

    3.2                 The Company's By-Laws, as amended September
                        21, 2004, filed as Exhibit 3.2 to the
                        Company's Quarterly Report on Form 10-Q for
                        the quarter ended September 30, 2004, are
                        incorporated herein by reference.

    4.1                 Alleghany Corporation Amended and Restated
                        Directors' Stock Option Plan effective as of
                        April 20, 1993, filed as Exhibit 10.1 to the
                        Company's Quarterly Report on Form 10-Q for
                        the quarter ended June 30, 1993, is
                        incorporated herein by reference.

    4.2                 Alleghany Corporation 2000 Directors' Stock
                        Option Plan effective as of April 28, 2000,
                        included as Exhibit A to the Company's Proxy
                        Statement dated March 27, 2000 filed in
                        connection with its Annual Meeting of
                        Stockholders held on April 28, 2000, is
                        incorporated herein by reference.

    4.3                 Alleghany Corporation 2005 Directors' Stock
                        Plan effective as of April 22, 2005,
                        included as Exhibit A to the Company's Proxy
                        Statement dated March 9, 2005 filed in
                        connection with its Annual Meeting of
                        Stockholders held on April 22, 2005, is
                        incorporated herein by reference.
</TABLE>

                                        4

<PAGE>

<TABLE>
<S>                     <C>
   4.4                  Alleghany Corporation Subsidiary Directors' Stock Option Plan.

   5                    Opinion of Dewey Ballantine LLP.

   23.1                 Consent of Dewey Ballantine LLP (included in Exhibit 5 hereto).

   23.2                 Consent of KPMG LLP.

   24                   Powers of Attorney.
</TABLE>

Item 9. Undertakings.

      (a) The undersigned registrant hereby undertakes:

            (1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this Registration Statement:

            (i) To include any prospectus required by Section 10(a)(3) of the
Securities Act;

            (ii) To reflect in the prospectus any facts or events arising after
the effective date of this Registration Statement (or the most recent
post-effective amendment thereof) which, individually or in the aggregate,
represent a fundamental change in the information set forth in this Registration
Statement. Notwithstanding the foregoing, any increase or decrease in volume of
securities offered (if the total dollar value of securities offered would not
exceed that which was registered) and any deviation from the low or high end of
the estimated maximum offering range may be reflected in the form of prospectus
filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the
changes in volume and price represent no more than a 20 percent change in the
maximum aggregate offering price set forth in the "Calculation of Registration
Fee" table in this effective Registration Statement;

            (iii) To include any material information with respect to the plan
of distribution not previously disclosed in this Registration Statement or any
material change to such information in this Registration Statement;

provided, however, that the undertakings set forth in paragraphs (a)(1)(i) and
(a)(1)(ii) above do not apply if the information required to be included in a
post-effective amendment by those paragraphs is contained in periodic reports
filed with or furnished to the Commission by the registrant pursuant to Section
13 or Section 15(d) of the Exchange Act that are incorporated by reference in
this Registration Statement.

            (2) That, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

                                        5

<PAGE>

            (3) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

      (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to Section 15(d) of the Exchange Act) that is
incorporated by reference in this Registration Statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

      (c) Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the registrant pursuant to the indemnification provisions summarized in Item
6 above or otherwise, the registrant has been advised that in the opinion of the
Commission such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.

                                       6

<PAGE>

                                   SIGNATURES

            Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of New York, State of New York, on August 8, 2005.

                                     ALLEGHANY CORPORATION

                                     By: /s/ Weston M. Hicks
                                         --------------------------------------
                                         Weston M. Hicks
                                         President

            Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the date indicated.

Date: August 8, 2005                 By:              *
                                         --------------------------------------
                                         Rex D. Adams
                                         Director

Date: August 8, 2005                 By:               *
                                         --------------------------------------
                                         John J. Burns, Jr.
                                         Vice Chairman of the Board and Director

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         Dan R. Carmichael
                                         Director

Date: August 8, 2005                 By: /s/ Roger B. Gorham
                                         --------------------------------------
                                         Roger B. Gorham
                                         Senior Vice President-Finance
                                         (principal financial officer)

Date: August 8, 2005                 By: /s/ Weston M. Hicks
                                         --------------------------------------
                                         Weston M. Hicks
                                         President and Director
                                         (principal executive officer)

                                      7

<PAGE>

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         Thomas S. Johnson
                                         Director

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         Allan P. Kirby, Jr.
                                         Director

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         F.M. Kirby
                                         Chairman of the Board and Director

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         William K. Lavin
                                         Director

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         Roger Noall
                                         Director

Date: August 8, 2005                 By: /s/ Peter R. Sismondo
                                         --------------------------------------
                                         Peter R. Sismondo
                                         Vice President, Controller, Treasurer
                                         and
                                         Assistant Secretary (principal
                                         accounting officer)

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         James F. Will
                                         Director

                            *By: /s/ Weston M. Hicks
                                 ------------------------
                                 Weston M. Hicks
                                 Attorney-in-Fact

                                       8

<PAGE>

                                INDEX TO EXHIBITS

<TABLE>
<CAPTION>
Exhibit Number                          Description
--------------           --------------------------------------------
<S>                      <C>
     3.1                 The Company's Restated Certificate of
                         Incorporation, as amended by Amendment
                         accepted and received for filing by the
                         Secretary of State of the State of Delaware
                         on June 23, 1988, filed as Exhibit 20 to the
                         Company's Quarterly Report on Form 10-Q for
                         the quarter ended June 30, 1988, is
                         incorporated herein by reference.

     3.2                 The Company's By-Laws, as amended September
                         21, 2004, filed as Exhibit 3.2 to the
                         Company's Quarterly Report on Form 10-Q for
                         the quarter ended September 30, 2004, are
                         incorporated herein by reference.

     4.1                 Alleghany Corporation Amended and Restated
                         Directors' Stock Option Plan effective as of
                         April 20, 1993, filed as Exhibit 10.1 to the
                         Company's Quarterly Report on Form 10-Q for
                         the quarter ended June 30, 1993, is
                         incorporated herein by reference.

     4.2                 Alleghany Corporation 2000 Directors' Stock
                         Option Plan effective as of April 28, 2000,
                         included as Exhibit A to the Company's Proxy
                         Statement dated March 27, 2000 filed in
                         connection with its Annual Meeting of
                         Stockholders held on April 28, 2000, is
                         incorporated herein by reference.

     4.3                 Alleghany Corporation 2005 Directors' Stock
                         Plan effective as of April 22, 2005,
                         included as Exhibit A to the Company's Proxy
                         Statement dated March 9, 2005 filed in
                         connection with its Annual Meeting of
                         Stockholders held on April 22, 2005, is
                         incorporated herein by reference.

     4.4                 Alleghany Corporation Subsidiary Directors'
                         Stock Option Plan.

     5                   Opinion of Dewey Ballantine LLP.

     23.1                Consent of Dewey Ballantine LLP (included in
                         Exhibit 5 hereto).

     23.2                Consent of KPMG LLP.

     24                  Powers of Attorney.
</TABLE>

                                       9
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{"company-data": {"conformed-name": "ALLEGHANY CORP /DE", "cik": "0000775368", "assigned-sic": "6361", "irs-number": "510283071", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-127309", "film-number": "051006500"}, "business-address": {"street1": "375 PARK AVENUE", "street2": "SUITE 3201", "city": "NEW YORK", "state": "NY", "zip": "10152", "phone": "2127521356"}, "mail-address": {"street1": "375 PARK AVENUE", "street2": "SUITE 3201", "city": "NEW YORK", "state": "NY", "zip": "10152"}, "former-company": {"former-conformed-name": "ALLEGHANY FINANCIAL CORP", "date-changed": "19870115"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 8, 2005

                                                           REGISTRATION NO. 333-
================================================================================
                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                          ----------------------------
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                        ---------------------------------

                              ALLEGHANY CORPORATION
             (Exact name of registrant as specified in its charter)

       DELAWARE                                       51-0283071
(STATE OF INCORPORATION)                (I.R.S. EMPLOYER IDENTIFICATION NUMBER)

          7 TIMES SQUARE TOWER
          NEW YORK, NEW YORK                                 10036
(ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                   (ZIP CODE)

     ALLEGHANY CORPORATION AMENDED AND RESTATED DIRECTORS' STOCK OPTION PLAN
             ALLEGHANY CORPORATION 2000 DIRECTORS' STOCK OPTION PLAN
                ALLEGHANY CORPORATION 2005 DIRECTORS' STOCK PLAN
          ALLEGHANY CORPORATION SUBSIDIARY DIRECTORS' STOCK OPTION PLAN
                            (FULL TITLE OF THE PLANS)

                                 ROBERT M. HART
              SENIOR VICE PRESIDENT, GENERAL COUNSEL AND SECRETARY
                              ALLEGHANY CORPORATION
                              7 TIMES SQUARE TOWER
                            NEW YORK, NEW YORK 10036
                                 (212) 752-1356
            (NAME, ADDRESS AND TELEPHONE NUMBER OF AGENT FOR SERVICE)

                         CALCULATION OF REGISTRATION FEE
PROPOSED MAXIMUM
TITLE OF SECURITIES TO BE   AMOUNT TO BE REGISTERED       PROPOSED MAXIMUM          AGGREGATE OFFERING            AMOUNT OF
        REGISTERED                     (1)             OFFERING PRICE PER SHARE          PRICE )               REGISTRATION FEE
-------------------------   -----------------------    ------------------------     ------------------         ----------------
Common Stock, par value        28,487 shares (2)                     (6)            $ 6,436,627.50 (7)            $  758
    $1.00 per share
Common Stock, par value        35,000 shares (3)                     (6)            $ 6,939,012.50 (7)            $  817
    $1.00 per share
Common Stock, par value        50,000 shares (4)               307.27(8)            $15,363,500.00 (8)            $1,809
    $1.00 per share
Common Stock, par value         7,000 shares (5)                     (6)            $ 1,467,281.40 (7)            $  173
    $1.00 per share
(1)   Pursuant to Rule 416(a) under the Securities Act of 1933, as amended, this
      Registration Statement also covers any additional shares of Common Stock
      which become issuable pursuant to the provisions of the plans listed above
      by reason of antidilution and other adjustments.

(2)   Up to 28,487 shares of Common Stock may be issued under the Alleghany
      Corporation Amended and Restated Directors' Stock Option Plan.

(3)   Up to 35,000 shares of Common Stock may be issued under the Alleghany
      Corporation 2000 Directors' Stock Option Plan.

(4)   Up to 50,000 shares of Common Stock may be issued under the Alleghany
      Corporation 2005 Directors' Stock Plan.

(5)   Up to 7,000 shares of Common Stock may be issued under the Alleghany
      Corporation Subsidiary Directors' Stock Option Plan.

(6)   The offering price per share varied from option grant to option grant.

(7)   Pursuant to Rule 457(h) of the Securities Act of 1933, as amended, solely
      for the purpose of calculating the registration fee, these amounts were
      estimated on the basis of the prices at which the options under the plans
      may be exercised.

(8)   Pursuant to Rule 457(h) of the Securities Act of 1933, as amended, solely
      for the purpose of calculating the registration fee, these amounts were
      estimated on the basis of the average of the high and low sales prices of
      the Common Stock as reported on the New York Stock Exchange on August 4,
      2005.

================================================================================
PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

            The document(s) containing the information specified by Part I of
this Form S-8 registration statement (this "Registration Statement") will be
sent or given to participants in the plans listed on the cover of this
Registration Statement (the "Plans") as specified in Rule 428(b)(1) promulgated
by the Securities and Exchange Commission (the "Commission") under the
Securities Act of 1933, as amended (the "Securities Act"). Such document(s) are
not being filed with the Commission either as part of this Registration
Statement or as prospectuses or prospectus supplements pursuant to Rule 424 but
taken together, along with the documents incorporated by reference in this
Registration Statement pursuant to Item 3 of Part II hereof, constitute a
prospectus that meets the requirements of Section 10(a) of the Securities Act.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

            The following documents filed with the Commission by Alleghany
Corporation (the "Company") are incorporated herein by reference and made a part
hereof:

      (a)   The Company's Annual Report on Form 10-K for the fiscal year ended
            December 31, 2004;

      (b)(i)The Company's Quarterly Report on Form 10-Q for the quarter ended
            March 31, 2005;

        (ii)The Company's Current Reports on Form 8-K filed on January 5,
            February 8, March 10, April 8, April 21, April 22, April 28,
            May 23, July 20 and July 25, 2005; and

      (c)   The description of the Company's Common Stock contained in the
            Company's Registration Statement on Form 10 filed pursuant to
            Section 12 of the Securities Exchange Act of 1934, as amended (the
            "Exchange Act"), which incorporates by reference certain portions of
            the Company's Proxy Statement dated November 26, 1986 relating to
            its Special Meeting of Stockholders held on December 19, 1986; such
            description is qualified in its entirety by reference to (i) the
            Company's Restated Certificate of Incorporation, as amended, and
            (ii) the Company's By-Laws, as amended, incorporated by reference as
            Exhibits 3.1 and 3.2, respectively, in this Registration Statement,
            and any amendment or report filed for the purpose of updating that
            description.

                                       2
All documents subsequently filed by the Company pursuant to Sections
13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment which indicates that all securities offered hereunder
have been sold or which deregisters all securities then remaining unsold
hereunder, shall be deemed to be incorporated by reference herein and to be a
part hereof from the date of filing of such documents. Any statement contained
in a document incorporated or deemed to be incorporated by reference herein
shall be deemed to be modified or superseded for purposes of this Registration
Statement to the extent that a statement contained herein (or in any other
subsequently filed document that also is or is deemed to be incorporated by
reference herein or therein) modifies or supersedes such statement. Any
statement so modified or superseded shall not be deemed, except as so modified
or superseded, to constitute a part of this Registration Statement.

            The consolidated financial statements and financial statement
schedules of the Company and its subsidiaries included in or incorporated by
reference in the Company's Annual Report on Form 10-K for the fiscal year ended
December 31, 2004 have been incorporated herein by reference in reliance upon
the reports, also incorporated herein by reference, of KPMG LLP, independent
registered public accounting firm, given on its authority as experts in
accounting and auditing.

Item 4. Description of Securities.

            Not applicable.

Item 5. Interests of Named Experts and Counsel.

            Not applicable.

Item 6. Indemnification of Directors and Officers.

            The Company is a Delaware corporation. Reference is made to Section
145 of the Delaware General Corporation Law as to indemnification by the Company
of its officers and directors. The general effect of such law is to empower a
corporation to indemnify any of its officers and directors against certain
expenses (including attorneys' fees), judgments, fines and amounts paid in
settlement actually and reasonably incurred by the person to be indemnified in
connection with certain actions, suits or proceedings (threatened, pending or
completed) if the person to be indemnified acted in good faith and in a manner
he reasonably believed to be in, or not opposed to, the best interests of the
corporation and, with respect to any criminal action or proceeding, had no
reasonable cause to believe his conduct was unlawful.

            Article Tenth of the Company's Restated Certificate of
Incorporation, as amended (which Restated Certificate of Incorporation is
incorporated herein by reference as Exhibit 3.1 in this Registration Statement),
provides for the indemnification of the Company's officers and directors in
accordance with the Delaware General Corporation Law, and includes, as permitted
by the Delaware General Corporation Law, certain limitations on the potential
personal liability of members of the Company's Board of

                                       3
Directors for monetary damages as a result of actions taken in their capacity as
Board members.

            The directors and officers of the Company are covered by insurance
policies indemnifying them against certain liabilities arising under the
Securities Act, which might be incurred by them in such capacities.

Item 7. Exemption from Registration Claimed.

            Not applicable.

Item 8. Exhibits.

            The following are filed as exhibits hereto.
Exhibit Number                         Description
--------------          --------------------------------------------
3.1                 The Company's Restated Certificate of
                        Incorporation, as amended by Amendment
                        accepted and received for filing by the
                        Secretary of State of the State of Delaware
                        on June 23, 1988, filed as Exhibit 20 to the
                        Company's Quarterly Report on Form 10-Q for
                        the quarter ended June 30, 1988, is
                        incorporated herein by reference.

    3.2                 The Company's By-Laws, as amended September
                        21, 2004, filed as Exhibit 3.2 to the
                        Company's Quarterly Report on Form 10-Q for
                        the quarter ended September 30, 2004, are
                        incorporated herein by reference.

    4.1                 Alleghany Corporation Amended and Restated
                        Directors' Stock Option Plan effective as of
                        April 20, 1993, filed as Exhibit 10.1 to the
                        Company's Quarterly Report on Form 10-Q for
                        the quarter ended June 30, 1993, is
                        incorporated herein by reference.

    4.2                 Alleghany Corporation 2000 Directors' Stock
                        Option Plan effective as of April 28, 2000,
                        included as Exhibit A to the Company's Proxy
                        Statement dated March 27, 2000 filed in
                        connection with its Annual Meeting of
                        Stockholders held on April 28, 2000, is
                        incorporated herein by reference.

    4.3                 Alleghany Corporation 2005 Directors' Stock
                        Plan effective as of April 22, 2005,
                        included as Exhibit A to the Company's Proxy
                        Statement dated March 9, 2005 filed in
                        connection with its Annual Meeting of
                        Stockholders held on April 22, 2005, is
                        incorporated herein by reference.
4
4.4                  Alleghany Corporation Subsidiary Directors' Stock Option Plan.

   5                    Opinion of Dewey Ballantine LLP.

   23.1                 Consent of Dewey Ballantine LLP (included in Exhibit 5 hereto).

   23.2                 Consent of KPMG LLP.

   24                   Powers of Attorney.
Item 9. Undertakings.

      (a) The undersigned registrant hereby undertakes:

            (1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this Registration Statement:

            (i) To include any prospectus required by Section 10(a)(3) of the
Securities Act;

            (ii) To reflect in the prospectus any facts or events arising after
the effective date of this Registration Statement (or the most recent
post-effective amendment thereof) which, individually or in the aggregate,
represent a fundamental change in the information set forth in this Registration
Statement. Notwithstanding the foregoing, any increase or decrease in volume of
securities offered (if the total dollar value of securities offered would not
exceed that which was registered) and any deviation from the low or high end of
the estimated maximum offering range may be reflected in the form of prospectus
filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the
changes in volume and price represent no more than a 20 percent change in the
maximum aggregate offering price set forth in the "Calculation of Registration
Fee" table in this effective Registration Statement;

            (iii) To include any material information with respect to the plan
of distribution not previously disclosed in this Registration Statement or any
material change to such information in this Registration Statement;

provided, however, that the undertakings set forth in paragraphs (a)(1)(i) and
(a)(1)(ii) above do not apply if the information required to be included in a
post-effective amendment by those paragraphs is contained in periodic reports
filed with or furnished to the Commission by the registrant pursuant to Section
13 or Section 15(d) of the Exchange Act that are incorporated by reference in
this Registration Statement.

            (2) That, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

                                        5
(3) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

      (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to Section 15(d) of the Exchange Act) that is
incorporated by reference in this Registration Statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

      (c) Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the registrant pursuant to the indemnification provisions summarized in Item
6 above or otherwise, the registrant has been advised that in the opinion of the
Commission such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.

                                       6
SIGNATURES

            Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of New York, State of New York, on August 8, 2005.

                                     ALLEGHANY CORPORATION

                                     By: /s/ Weston M. Hicks
                                         --------------------------------------
                                         Weston M. Hicks
                                         President

            Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the date indicated.

Date: August 8, 2005                 By:              *
                                         --------------------------------------
                                         Rex D. Adams
                                         Director

Date: August 8, 2005                 By:               *
                                         --------------------------------------
                                         John J. Burns, Jr.
                                         Vice Chairman of the Board and Director

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         Dan R. Carmichael
                                         Director

Date: August 8, 2005                 By: /s/ Roger B. Gorham
                                         --------------------------------------
                                         Roger B. Gorham
                                         Senior Vice President-Finance
                                         (principal financial officer)

Date: August 8, 2005                 By: /s/ Weston M. Hicks
                                         --------------------------------------
                                         Weston M. Hicks
                                         President and Director
                                         (principal executive officer)

                                      7
Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         Thomas S. Johnson
                                         Director

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         Allan P. Kirby, Jr.
                                         Director

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         F.M. Kirby
                                         Chairman of the Board and Director

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         William K. Lavin
                                         Director

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         Roger Noall
                                         Director

Date: August 8, 2005                 By: /s/ Peter R. Sismondo
                                         --------------------------------------
                                         Peter R. Sismondo
                                         Vice President, Controller, Treasurer
                                         and
                                         Assistant Secretary (principal
                                         accounting officer)

Date: August 8, 2005                 By:                *
                                         --------------------------------------
                                         James F. Will
                                         Director

                            *By: /s/ Weston M. Hicks
                                 ------------------------
                                 Weston M. Hicks
                                 Attorney-in-Fact

                                       8
INDEX TO EXHIBITS
Exhibit Number                          Description
--------------           --------------------------------------------
3.1                 The Company's Restated Certificate of
                         Incorporation, as amended by Amendment
                         accepted and received for filing by the
                         Secretary of State of the State of Delaware
                         on June 23, 1988, filed as Exhibit 20 to the
                         Company's Quarterly Report on Form 10-Q for
                         the quarter ended June 30, 1988, is
                         incorporated herein by reference.

     3.2                 The Company's By-Laws, as amended September
                         21, 2004, filed as Exhibit 3.2 to the
                         Company's Quarterly Report on Form 10-Q for
                         the quarter ended September 30, 2004, are
                         incorporated herein by reference.

     4.1                 Alleghany Corporation Amended and Restated
                         Directors' Stock Option Plan effective as of
                         April 20, 1993, filed as Exhibit 10.1 to the
                         Company's Quarterly Report on Form 10-Q for
                         the quarter ended June 30, 1993, is
                         incorporated herein by reference.

     4.2                 Alleghany Corporation 2000 Directors' Stock
                         Option Plan effective as of April 28, 2000,
                         included as Exhibit A to the Company's Proxy
                         Statement dated March 27, 2000 filed in
                         connection with its Annual Meeting of
                         Stockholders held on April 28, 2000, is
                         incorporated herein by reference.

     4.3                 Alleghany Corporation 2005 Directors' Stock
                         Plan effective as of April 22, 2005,
                         included as Exhibit A to the Company's Proxy
                         Statement dated March 9, 2005 filed in
                         connection with its Annual Meeting of
                         Stockholders held on April 22, 2005, is
                         incorporated herein by reference.

     4.4                 Alleghany Corporation Subsidiary Directors'
                         Stock Option Plan.

     5                   Opinion of Dewey Ballantine LLP.

     23.1                Consent of Dewey Ballantine LLP (included in
                         Exhibit 5 hereto).

     23.2                Consent of KPMG LLP.

     24                  Powers of Attorney.
9