<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-11-12</periodOfReport>

    <issuer>
        <issuerCik>0000811830</issuerCik>
        <issuerName>SOVEREIGN BANCORP INC</issuerName>
        <issuerTradingSymbol>SOV</issuerTradingSymbol>
    </issuer>

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            <rptOwnerCik>0000891478</rptOwnerCik>
            <rptOwnerName>Banco Santander, S.A.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PASEO DE PEREDA 9-12</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANTANDER</rptOwnerCity>
            <rptOwnerState>U3</rptOwnerState>
            <rptOwnerZipCode>39004</rptOwnerZipCode>
            <rptOwnerStateDescription>SPAIN</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
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            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
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    </reportingOwner>

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    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>James H. Bathon</signatureName>
        <signatureDate>2008-11-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
