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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 O5UZkjBsfeFWVbXjhfiWmzTiGk+lBFoqcjLLJZeyOfX8fAsxL8szGlClYdduBeog
 8tVfGJ9zmySxxKnCWpfxwQ==

<SEC-DOCUMENT>0000036966-07-000046.txt : 20070424
<SEC-HEADER>0000036966-07-000046.hdr.sgml : 20070424
<ACCEPTANCE-DATETIME>20070424115039
ACCESSION NUMBER:		0000036966-07-000046
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20070420
FILED AS OF DATE:		20070424
DATE AS OF CHANGE:		20070424

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FIRST HORIZON NATIONAL CORP
		CENTRAL INDEX KEY:			0000036966
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				620803242
		STATE OF INCORPORATION:			TN
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		165 MADISON AVENUE
		CITY:			MEMPHIS
		STATE:			TN
		ZIP:			38103
		BUSINESS PHONE:		9018186232

	MAIL ADDRESS:	
		STREET 1:		165 MADISON AVENUE
		CITY:			MEMPHIS
		STATE:			TN
		ZIP:			38103

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FIRST TENNESSEE NATIONAL CORP
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FIRST TENNESSEE BANKS INC
		DATE OF NAME CHANGE:	19600201

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			JOHNSON HARRY A III
		CENTRAL INDEX KEY:			0001224972

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15185
		FILM NUMBER:		07783618

	BUSINESS ADDRESS:	
		STREET 1:		FIRST TENNESSEE NATIONAL CORP
		STREET 2:		165 MADISON AVENUE
		CITY:			MEMPHIS
		STATE:			TN
		ZIP:			38103
		BUSINESS PHONE:		9015235679

	MAIL ADDRESS:	
		STREET 1:		165 MADISON AVENUE
		CITY:			MEMPHIS
		STATE:			TN
		ZIP:			38103
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-04-20</periodOfReport>

    <issuer>
        <issuerCik>0000036966</issuerCik>
        <issuerName>FIRST HORIZON NATIONAL CORP</issuerName>
        <issuerTradingSymbol>FHN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001224972</rptOwnerCik>
            <rptOwnerName>JOHNSON HARRY A III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>FIRST HORIZON NATIONAL CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>165 MADISON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>MEMPHIS</rptOwnerCity>
            <rptOwnerState>TN</rptOwnerState>
            <rptOwnerZipCode>38103</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP &amp; General Counsel</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>39.66</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-04-20</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>29375</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2010-04-20</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-04-20</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>29375</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>29375</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Options are exercisable 50% after 3 yrs, 100% after 4 yrs.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>by Clyde A. Billings, Jr., attorney-in-fact</signatureName>
        <signatureDate>2007-04-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>powerofattorney.txt
<DESCRIPTION>POWER OF ATTORNEY LETTER
<TEXT>
POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS, that the undersigned does hereby
constitute and appoint Clyde A. Billings, Jr., John A. Niemoeller,
and Shannon M. Hernandez jointly and each of them severally, the
undersigned's true and lawful attorney-in-fact and agent, with full
power of substitution and resubstitution, for the undersigned and in the
undersigned's name, place and stead, in any and all capacities, to:

(1) execute for and on behalf of the undersigned, in the undersigned's
capacity as an officer and/or director of First Tennessee National
Corporation (the "Corporation"), Forms 3, 4 and 5 and any and all amend-
ments thereto in accordance with Section 16(a) of the Securities Exchange
Act of 1934, as amended (the "Exchange Act"), and the rules thereunder;
and

(2) do and perform any and all acts on behalf of the undersigned which
may be necessary or desirable to complete and execute any such Forms 3,
4 or 5 or an amendment thereto and timely file such form with the
Securities and Exchange Commission and any stock exchange or similar
authority; and

(3) take any other action of any type whatsoever in connection with
the foregoing which, in the opinion of such attorney-in-fact, may be
of benefit to, in the best interest of, or legally required by, the
undersigned, it being understood that the documents being executed
by such attorney-in-fact on behalf of the undersigned pursuant to
this Power of Attorney shall be in such form and shall contain such
terms and conditions as such attorney-in-fact may approve in such
attorney-in-fact's discretion.

The undersigned hereby grants to each such attorney-in-fact full power
and authority to do and perform any and every act and thing whatsoever
requisite, necessary, or proper to be done in the exercise of any of
the rights and powers herein granted, as fully to all intents and
purposes as the undersigned might or could do if personally present,
hereby ratifying and confirming all that such attorney-in-fact, or such
attorney-in-fact's substitute or substitutes, shall lawfully do or cause
to be done by virtue of this Power of Attorney and the rights and
powers herein granted. The undersigned acknowledges that the foregoing
attorneys-in-fact, in servicing in such capacity at the request of the
undersigned, are not assuming, nor is the Corporation assuming, any
of the undersigned's responsibilities to comply with Section 16 of the
Exchange Act.

This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4 and 5 with respect
to the undersigned's holdings of and transactions in securities issued
by the Corporation, unless earlier revoked by the undersigned in a
signed writing delivered to the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney
as of this 16th day of March, 2007.

/s/ Harry A. Johnson, III
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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