-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 RHGvFegKpTUm+F7dPGRZzAfgfnDqZWNvBzNn4KuWKa8w7970KKoqfYLeWxORe5fO
 xIAYgx6l0n/H4XIp8UuDSg==

<SEC-DOCUMENT>0001181359-03-000010.txt : 20031010
<SEC-HEADER>0001181359-03-000010.hdr.sgml : 20031010
<ACCEPTANCE-DATETIME>20031010161953
ACCESSION NUMBER:		0001181359-03-000010
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031008
FILED AS OF DATE:		20031010

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BYRNE JOHN JOSEPH
		CENTRAL INDEX KEY:			0001181359
		STANDARD INDUSTRIAL CLASSIFICATION:	FIRE, MARINE & CASUALTY INSURANCE [6331]
		STATE OF INCORPORATION:			D0
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08993
		FILM NUMBER:		03937240

	BUSINESS ADDRESS:	
		STREET 1:		C/O WHITE MOUNTAINS INSURANCE GROUP, LTD
		STREET 2:		80 SOUTH MAIN STREET
		CITY:			HANOVER
		STATE:			NH
		ZIP:			03755
		BUSINESS PHONE:		6036402200

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WHITE MOUNTAINS INSURANCE GROUP LTD
		CENTRAL INDEX KEY:			0000776867
		STANDARD INDUSTRIAL CLASSIFICATION:	FIRE, MARINE & CASUALTY INSURANCE [6331]
		IRS NUMBER:				942708455
		STATE OF INCORPORATION:			D0
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		80 SOUTH MAIN STREET
		CITY:			HANOVER
		STATE:			NH
		ZIP:			03755
		BUSINESS PHONE:		603 640 2200

	MAIL ADDRESS:	
		STREET 1:		80 SOUTH MAIN STREET
		CITY:			HANOVER
		STATE:			NH
		ZIP:			03755

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	WHITE MOUNTAINS INSURANCE GROUP INC
		DATE OF NAME CHANGE:	19990603

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FUND AMERICAN ENTERPRISES HOLDINGS INC
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FUND AMERICAN COMPANIES INC
		DATE OF NAME CHANGE:	19920701
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-10-08</periodOfReport>
    <issuer>
        <issuerCik>0000776867</issuerCik>
        <issuerName>WHITE MOUNTAINS INSURANCE GROUP LTD</issuerName>
        <issuerTradingSymbol>WTM</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001181359</rptOwnerCik>
            <rptOwnerName>BYRNE JOHN JOSEPH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WHITE MOUNTAINS INSURANCE GROUP, LTD</rptOwnerStreet1>
            <rptOwnerStreet2>80 SOUTH MAIN STREET</rptOwnerStreet2>
            <rptOwnerCity>HANOVER</rptOwnerCity>
            <rptOwnerState>NH</rptOwnerState>
            <rptOwnerZipCode>03755</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>1</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Shares</value></securityTitle><transactionDate><value>2003-10-08</value></transactionDate><deemedExecutionDate><value>2003-10-08</value></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>P</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>100</value><footnoteId id="F1"/></transactionShares><transactionPricePerShare><value>428.00</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>426102</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeHolding><securityTitle><value>Common Shares</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>631334</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By GRAT (Family Trusts)</value></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Shares</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1150</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By wife</value></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Shares</value></securi
tyTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>401(k)</value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><footnotes><footnote id="F1">Reporting Person purchased the first 100 Common Shares of WTM traded on the Bermuda Stock Exchange.</footnote></footnotes><remarks/><ownerSignature><signatureName>John J. Byrne</signatureName><signatureDate>2003-10-10</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----