-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 SODmINnuy0ObWF56eGkUxsVwarEmaHHzwzGq26Wlv8pvy4R2ayUvo4Whk88vuF+u
 Rb8Pm5HRom24Fn4BHLmAaQ==

<SEC-DOCUMENT>0000011544-03-000006.txt : 20031223
<SEC-HEADER>0000011544-03-000006.hdr.sgml : 20031223
<ACCEPTANCE-DATETIME>20031223162633
ACCESSION NUMBER:		0000011544-03-000006
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031223
FILED AS OF DATE:		20031223

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BROCKBANK MARK ELLWOOD
		CENTRAL INDEX KEY:			0001068341

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15202
		FILM NUMBER:		031071372

	BUSINESS ADDRESS:	
		STREET 1:		48 GLOUCESTER SQUARE
		STREET 2:		LONDON W2 2TQ
		CITY:			ENGLAND

	MAIL ADDRESS:	
		STREET 1:		ROC FLEURI APT C41
		STREET 2:		1 RUE DU TENAO
		CITY:			MONTE CARLO
		STATE:			O9
		ZIP:			98000

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BERKLEY W R CORP
		CENTRAL INDEX KEY:			0000011544
		STANDARD INDUSTRIAL CLASSIFICATION:	FIRE, MARINE & CASUALTY INSURANCE [6331]
		IRS NUMBER:				221867895
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		475 STEAMBOAT ROAD
		STREET 2:		.
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
		BUSINESS PHONE:		2036293000

	MAIL ADDRESS:	
		STREET 1:		475 STEAMBOAT ROAD
		STREET 2:		.
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-12-23</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000011544</issuerCik>
        <issuerName>BERKLEY W R CORP</issuerName>
        <issuerTradingSymbol>BER</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001068341</rptOwnerCik>
            <rptOwnerName>BROCKBANK MARK ELLWOOD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ROC FLEURI APT C41</rptOwnerStreet1>
            <rptOwnerStreet2>1 RUE DU TENAO</rptOwnerStreet2>
            <rptOwnerCity>MONTE CARLO</rptOwnerCity>
            <rptOwnerState>O9</rptOwnerState>
            <rptOwnerZipCode>98000</rptOwnerZipCode>
            <rptOwnerStateDescription>MONACO</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-12-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>29000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>34.1402</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>356525</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>



    <ownerSignature>
        <signatureName>Mark E. Brockbank</signatureName>
        <signatureDate>2003-12-23</signatureDate>
    </ownerSignature>

</ownershipDocument>

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