UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    Form 13F

                               Form 13F COVER PAGE

Report for the Calendar Year or Quarter Ended: December 31, 2007

Check here if Amendment [ ]; Amendment Number: ______

     This Amendment (Check only one): [ ] is a restatement.
                                      [ ] adds new holdings entries.

Institutional Investment Manager Filing this Report:

Name:    Alleghany Corporation
Address: 7 Times Square Tower, 17th Floor
         New York, NY 10036

Form 13F File Number: 28-1590

The institutional investment manager filing this report and the person by whom
it is signed hereby represent that the person signing the report is authorized
to submit it, that all information contained herein is true, correct and
complete, and that it is understood that all required items, statements,
schedules, lists, and tables, are considered integral parts of this form.

Person Signing this Report on Behalf of Reporting Manager:

Name:  Peter R. Sismondo
Title: Vice President
Phone: 212-752-1356

Signature, Place, and Date of Signing:


/s/ Peter R. Sismondo                   New York, NY    February 12, 2008
-------------------------------------   -------------   -----------------
[Signature]                             [City, State]   [Date]



Report Type (Check only one):

[X]  13F HOLDINGS REPORT. (Check here if all holdings of this reporting manager
     are reported in this report.)

[ ]  13F NOTICE. (Check here if no holdings reported are in this report, and all
     holdings are reported by other reporting manager(s).)

[ ]  13F COMBINATION REPORT. (Check here if a portion of the holdings for this
     reporting manager are reported in this report and a portion are reported by
     other reporting manager(s).)



                              Form 13F SUMMARY PAGE

Report Summary:

Number of Other Included Managers:                 3
Form 13F Information Table Entry Total:           74
Form 13F Information Table Value Total:   $1,355,827
                                          (thousands)

List of Other Included Managers:

No.   Form 13F File Number                 Name
2                            RSUI Indemnity Company
3                            Capitol Indemnity Corporation
4                            Alleghany Insurance Holdings LLC


SECURITIES AND EXCHANGE COMMISSIONS FORM 13F INFORMATION
PREPARED FOR ALLEGHANY CORPORATION
AS OF 12/31/07



          COLUMN 1              COLUMN 2     COLUMN 3  COLUMN 4       COLUMN 5         COLUMN 6     COLUMN 7    COLUMN 8
          --------           -------------- --------- --------- ------------------- --------------- -------- --------------
                                                                                       INVESTMENT                VOTING
                                                                                       DISCRETION               AUTHORITY
                                                        MARKET                      ---------------          --------------
                                                        VALUE     SHRS OR  SH/ PUT/ SOLE SHRD OTHER          SOLE SHRD NONE
       NAME OF ISSUER        TITLE OF CLASS   CUSIP    (X 1000)  PRIN AMT  PRN CALL  (A)  (B)  (C)   MANAGER  (A)  (B)  (C)
       --------------        -------------- --------- --------- ---------- --- ---- ---- ---- ----- -------- ---- ---- ----
                                                                                
NABORS INDUSTRIES LTD        SHS            G6359F103       959     35,000 SH              X            1      X
NABORS INDUSTRIES LTD        SHS            G6359F103    23,145    845,000 SH              X            2      X
NABORS INDUSTRIES LTD        SHS            G6359F103     3,424    125,000 SH              X            3      X
PLATINUM UNDERWRITER HLDGS L COM            G7127P100    13,691    385,000 SH                   X       4      X
WEATHERFORD INTERNATIONAL LT COM            G95089101     1,715     25,000 SH              X            1      X
WEATHERFORD INTERNATIONAL LT COM            G95089101     5,208     75,920 SH              X            2      X
WEATHERFORD INTERNATIONAL LT COM            G95089101     4,459     65,000 SH              X            3      X
UBS AG                       SHS NEW        H98231338     1,610     35,000 SH              X            1      X
UBS AG                       SHS NEW        H98231338    20,470    445,000 SH              X            2      X
UBS AG                       SHS NEW        H98231338     8,280    180,000 SH              X            3      X
AT&T INC                     COM            00206R102     1,662     40,000 SH                   X       4      X
AGILENT TECHNOLOGIES INC     COM            00846U101     1,102     30,000 SH                   X       4      X
ALEXANDER & BALDWIN INC      COM            014482103     1,033     20,000 SH                   X       4      X
AMERICAN EXPRESS CO          COM            025816109     1,561     30,000 SH                   X       4      X
AMERICAN INTL GROUP INC      COM            026874107     1,166     20,000 SH                   X       4      X
APACHE CORP                  COM            037411105    50,275    467,500 SH              X            2      X
APACHE CORP                  COM            037411105    13,174    122,500 SH              X            3      X
APPLERA CORP                 COM AP BIO GRP 038080103     1,696     50,000 SH                   X       4      X
APPLIED MATLS INC            COM            038222105       888     50,000 SH                   X       4      X
AUTODESK INC                 COM            052769106     1,493     30,000 SH                   X       4      X
AUTOMATIC DATA PROCESSING IN COM            053015103       891     20,000 SH                   X       4      X
BELO CORP                    COM SER A      080555105       872     50,000 SH                   X       4      X
BERKSHIRE HATHAWAY INC DEL   CL B           084670207     1,894        400 SH                   X       4      X
BOEING CO                    COM            097023105     1,312     15,000 SH                   X       4      X
BURLINGTON NORTHN SANTA FE C COM            12189T104   416,150  5,000,000 SH         X                 1      X
CATERPILLAR INC DEL          COM            149123101     1,814     25,000 SH                   X       4      X
CHESAPEAKE ENERGY CORP       COM            165167107     1,960     50,000 SH              X            1      X
CHESAPEAKE ENERGY CORP       COM            165167107     1,960     50,000 SH              X            2      X
CHESAPEAKE ENERGY CORP       COM            165167107     4,900    125,000 SH              X            3      X
CHEVRON CORP NEW             COM            166764100     1,867     20,000 SH              X            1      X
CHEVRON CORP NEW             COM            166764100    38,732    415,000 SH              X            2      X
CHEVRON CORP NEW             COM            166764100    12,133    130,000 SH              X            3      X
CHEVRON CORP NEW             COM            166764100    10,266    110,000 SH                   X       4      X
CHUBB CORP                   COM            171232101     1,637     30,000 SH                   X       4      X
COCA COLA CO                 COM            191216100     1,534     25,000 SH                   X       4      X
COMMERCE BANCORP INC NJ      COM            200519106     9,039    237,000 SH              X            2      X
COMMERCE BANCORP INC NJ      COM            200519106       496     13,000 SH              X            3      X
CONOCOPHILLIPS               COM            20825C104     1,766     20,000 SH              X            1      X
CONOCOPHILLIPS               COM            20825C104    28,256    320,000 SH              X            2      X
CONOCOPHILLIPS               COM            20825C104    12,804    145,000 SH              X            3      X
CONOCOPHILLIPS               COM            20825C104    45,033    510,000 SH                   X       4      X
COSTCO WHSL CORP NEW         COM            22160K105     2,093     30,000 SH                   X       4      X
DARWIN PROFESSIONAL UNDERWRI COM            237502109   222,845  9,371,096 SH                   X       4      X
DEERE & CO                   COM            244199105     2,794     30,000 SH                   X       4      X
DEVON ENERGY CORP NEW        COM            25179M103     1,778     20,000 SH              X            1      X
DEVON ENERGY CORP NEW        COM            25179M103    47,345    532,500 SH              X            2      X
DEVON ENERGY CORP NEW        COM            25179M103    13,781    155,000 SH              X            3      X
DISNEY WALT CO               COM DISNEY     254687106     1,453     45,000 SH                   X       4      X
DOW CHEM CO                  COM            260543103       788     20,000 SH                   X       4      X
DU PONT EI DE NEMOURS & CO   COM            263534109     1,323     30,000 SH                   X       4      X
EXXON MOBIL CORP             COM            30231G102     2,811     30,000 SH                   X       4      X
FEDEX CORP                   COM            31428X106     1,338     15,000 SH                   X       4      X
FIFTH THIRD BANCOP           COM            316773100       503     20,000 SH                   X       4      X
GENERAL ELECTRIC CO          COM            369604103     2,039     55,000 SH              X            1      X
GENERAL ELECTRIC CO          COM            369604103     7,229    195,000 SH              X            2      X
GENERAL ELECTRIC CO          COM            369604103     4,819    130,000 SH              X            3      X
GENERAL ELECTRIC CO          COM            369604103     1,668     45,000 SH                   X       4      X
HSBC HLDGS PLC               SPON ADR NEW   404280406    16,742    200,000 SH              X            2      X
HSBC HLDGS PLC               SPON ADR NEW   404280406     8,371    100,000 SH              X            3      X
HOME DEPOT INC               COM            437076102       539     20,000 SH                   X       4      X
INTEL CORP                   COM            458140100     1,866     70,000 SH                   X       4      X
INTERNATIONAL BUSINESS MACHS COM            459200101     1,297     12,000 SH                   X       4      X
INTUIT                       COM            461202103       632     20,000 SH                   X       4      X
JOHNSON AND JOHNSON          COM            478160104     1,334     20,000 SH                   X       4      X
KELLOGG                      COM            487836108     1,049     20,000 SH                   X       4      X
KRAFT FOODS INC              CL A           50075N104     1,795     55,000 SH              X            1      X



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SECURITIES AND EXCHANGE COMMISSIONS FORM 13F INFORMATION
PREPARED FOR ALLEGHANY CORPORATION
AS OF 12/31/07



          COLUMN 1              COLUMN 2     COLUMN 3  COLUMN 4       COLUMN 5         COLUMN 6     COLUMN 7    COLUMN 8
          --------           -------------- --------- --------- ------------------- --------------- -------- --------------
                                                                                       INVESTMENT                VOTING
                                                                                       DISCRETION               AUTHORITY
                                                        MARKET                      ---------------          --------------
                                                        VALUE     SHRS OR  SH/ PUT/ SOLE SHRD OTHER          SOLE SHRD NONE
       NAME OF ISSUER        TITLE OF CLASS   CUSIP    (X 1000)  PRIN AMT  PRN CALL  (A)  (B)  (C)   MANAGER  (A)  (B)  (C)
       --------------        -------------- --------- --------- ---------- --- ---- ---- ---- ----- -------- ---- ---- ----
                                                                                
KRAFT FOODS INC              CL A           50075N104    21,862    670,000 SH              X            2      X
KRAFT FOODS INC              CL A           50075N104     5,058    155,000 SH              X            3      X
LAUDER ESTEE COS INC         CL A           518439104     1,090     25,000 SH                   X       4      X
LIBERTY MEDIA HLDG CORP      CAP COM SER A  53071M302       466      4,000 SH                   X       4      X
LILLY ELI & CO               COM            532457108     1,602     30,000 SH                   X       4      X
LINCOLN NATIONAL CORP IND    COM            534187109     1,046     17,963 SH                   X       4      X
MANPOWER INC                 COM            56418H100       854     15,000 SH                   X       4      X
MEDTRONIC INC                COM            585055106     1,508     30,000 SH                   X       4      X
MERRILL LYNCH & CO INC       COM            590188108     1,610     30,000 SH              X            1      X
MERRILL LYNCH & CO INC       COM            590188108    15,030    280,000 SH              X            2      X
MERRILL LYNCH & CO INC       COM            590188108     4,831     90,000 SH              X            3      X
MICROSOFT CORP               COM            594918104     2,492     70,000 SH                   X       4      X
MILLIPORE CORP               COM            601073109     1,464     20,000 SH                   X       4      X
NEWS CORP                    CL A           65248E104     1,434     70,000 SH                   X       4      X
NOBLE ENERGY INC             COM            655044105     2,386     30,000 SH                   X       4      X
NORDSTROM INC                COM            655664100     1,102     30,000 SH                   X       4      X
NOVARTIS AG                  SPONSORED ADR  66987V109     1,358     25,000 SH                   X       4      X
OLD REP INTL CORP            COM            680223104     1,926    125,000 SH              X            1      X
OLD REP INTL CORP            COM            680223104     1,541    100,000 SH              X            2      X
OLD REP INTL CORP            COM            680223104       385     25,000 SH              X            3      X
OLD REP INTL CORP            COM            680223104    21,574  1,400,000 SH                   X       4      X
PFIZER INC                   COM            717081103     1,818     80,000 SH              X            1      X
PFIZER INC                   COM            717081103    15,343    675,000 SH              X            2      X
PFIZER INC                   COM            717081103     5,569    245,000 SH              X            3      X
PROCTER & GAMBLE CO          COM            742718109    15,802    215,227 SH              X            2      X
PROCTER & GAMBLE CO          COM            742718109    10,572    144,000 SH              X            3      X
PROCTER & GAMBLE CO          COM            742718109     2,203     30,000 SH                   X       4      X
SCHLUMBERGER LTD             COM            806857108     2,459     25,000 SH                   X       4      X
SIGMA ALDRICH CORP           COM            826552101     1,638     30,000 SH                   X       4      X
SONY CORP                    ADR NEW        835699307     1,358     25,000 SH                   X       4      X
STATE STR CORP               COM            857477103     1,218     15,000 SH                   X       4      X
SYSCO CORP                   COM            871829107       936     30,000 SH                   X       4      X
TESORO CORP                  COM            881609101    20,273    425,000 SH              X            2      X
TEXAS INSTRS INC             COM            882508104       668     20,000 SH                   X       4      X
3M CO                        COM            88579Y101     1,855     22,000 SH                   X       4      X
VALERO ENERGY CORP NEW       COM            91913Y100     1,401     20,000 SH              X            1      X
VALERO ENERGY CORP NEW       COM            91913Y100    21,709    310,000 SH              X            2      X
VALERO ENERGY CORP NEW       COM            91913Y100     9,804    140,000 SH              X            3      X
WACHOVIA CORP 2ND NEW        COM            929903102     1,521     40,000 SH              X            1      X
WACHOVIA CORP 2ND NEW        COM            929903102    23,388    615,000 SH              X            2      X
WACHOVIA CORP 2ND NEW        COM            929903102     7,036    185,000 SH              X            3      X
WACHOVIA CORP 2ND NEW        COM            929903102     1,521     40,000 SH                   X       4      X
WAL MART STORES INC          COM            931142103     2,139     45,000 SH                   X       4      X
WASHINGTON POST CO           CL B           939640108       791      1,000 SH                   X       4      X
WEYERHAUSER CO               COM            962166104     1,475     20,000 SH                   X       4      X
WYETH                        COM            983024100     1,105     25,000 SH              X            1      X
WYETH                        COM            983024100     8,396    190,000 SH              X            2      X
WYETH                        COM            983024100     2,651     60,000 SH              X            3      X
                                                      --------- ----------
GRAND TOTAL                                           1,355,827 28,541,106
                                                      ========= ==========



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