<?xml version="1.0"?><ownershipDocument>    <schemaVersion>X0101</schemaVersion><documentType>4</documentType><periodOfReport>2003-05-06</periodOfReport><issuer><issuerCik>1064728</issuerCik>        <issuerName>PEABODY ENERGY CORP</issuerName><issuerTradingSymbol>BTU</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>1214513</rptOwnerCik>            <rptOwnerName>RUSNACK WILLIAM C</rptOwnerName>        </reportingOwnerId>        <reportingOwnerAddress>            <rptOwnerStreet1>  </rptOwnerStreet1>            <rptOwnerStreet2>  </rptOwnerStreet2>            <rptOwnerCity>  </rptOwnerCity>            <rptOwnerState>  </rptOwnerState>            <rptOwnerZipCode>  </rptOwnerZipCode>        </reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle></officerTitle><otherText></otherText></reportingOwnerRelationship></reportingOwner><derivativeSecurity><securityTitle><value>Director Stock Option (right to buy)</value></securityTitle><conversionOrExercisePrice><value>28.51</value></conversionOrExercisePrice><transactionDate><value>2003-05-06</value></transactionDate><deemedExecutionDate><value>2003-05-06</value></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>1754</value></transactionShares><transactionValue><value>0</value></transactionValue><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2004-05-06</value><footnoteId id="F1" /></exerciseDate><expirationDate><value>2013-05-06</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>1754</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>4549</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></derivativeSecurity><footnotes><footnote id="F1">The options vest in three equal annual installments beginning on May 6, 2004.</footnote></footnotes><ownerSignature><signatureName>By: /s/ Joseph W. Bean, Attorney-in-Fact</signatureName><signatureDate>2003-05-07</signatureDate></ownerSignature></ownershipDocument>

