<SEC-DOCUMENT>0001096343-23-000073.txt : 20230428
<SEC-HEADER>0001096343-23-000073.hdr.sgml : 20230428
<ACCEPTANCE-DATETIME>20230428163722
ACCESSION NUMBER:		0001096343-23-000073
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20230115
FILED AS OF DATE:		20230428
DATE AS OF CHANGE:		20230428

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Noble Jeremy Andrew
		CENTRAL INDEX KEY:			0001751358

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15811
		FILM NUMBER:		23867270

	MAIL ADDRESS:	
		STREET 1:		4521 HIGHWOODS PARKWAY
		CITY:			GLEN ALLEN
		STATE:			VA
		ZIP:			23060

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MARKEL CORP
		CENTRAL INDEX KEY:			0001096343
		STANDARD INDUSTRIAL CLASSIFICATION:	FIRE, MARINE & CASUALTY INSURANCE [6331]
		IRS NUMBER:				541959284
		STATE OF INCORPORATION:			VA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		4521 HIGHWOODS PARKWAY
		CITY:			GLEN ALLEN
		STATE:			VA
		ZIP:			23060-6148
		BUSINESS PHONE:		8047470136

	MAIL ADDRESS:	
		STREET 1:		4521 HIGHWOODS PKWY
		CITY:			GLEN ALLEN
		STATE:			VA
		ZIP:			23060

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MARKEL HOLDINGS INC
		DATE OF NAME CHANGE:	19991005
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_168271422988123.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0407</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-01-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001096343</issuerCik>
        <issuerName>MARKEL CORP</issuerName>
        <issuerTradingSymbol>MKL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001751358</rptOwnerCik>
            <rptOwnerName>Noble Jeremy Andrew</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MARKEL CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>4521 HIGHWOODS PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>GLEN ALLEN</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>23060</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President, Insurance</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2023-01-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1.1726</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1295.96</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2349.7629</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2023-03-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value>E</value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4.4207</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1085.80</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2354.1836</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>228.89</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401(K) Plan</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares acquired under the non-qualified component of the Markel Corporation 2020 Employee Stock Purchase Plan.</footnote>
        <footnote id="F2">Shares acquired under the qualified component of the Markel Corporation 2020 Employee Stock Purchase Plan in a transaction exempt under Exchange Act Rule 16b-3(c).</footnote>
        <footnote id="F3">Between December 31, 2022 and March 31, 2023, Mr. Noble acquired 5.1040 share(s) under the Markel Corporation 401(K) Plan. The information reported herein is based on the plan balance as of March 31, 2023.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Karen O. Earls, Attorney-in-fact for Jeremy Andrew Noble</signatureName>
        <signatureDate>2023-04-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
