Amendment No. 1 to Rights Agreement with Computershare Trust Company, N.A.



 Exhibit 4.9 
 AMENDMENT NO. 1 TO THE 
 RIGHTS AGREEMENT 
 OF THE HANOVER INSURANCE GROUP, INC. 
 This Amendment No. 1, dated as of December 30, 2005 (this “Amendment”), amends the Rights Agreement dated as of December 16, 1997 (the “Rights Agreement”), between The Hanover Insurance Group, Inc., a
Delaware corporation formerly known as Allmerica Financial Corporation (the “Company”), and Computershare Trust Company, N.A., a nationally chartered trust company (as successor to First Chicago Trust Company of New York, a New York trust
company) as Rights Agent (the “Rights Agent”). Terms defined in the Rights Agreement and not otherwise defined herein are used herein as so defined. 
 WITNESSETH: 
 WHEREAS, on December 16, 1997, the Board of Directors of the Company (the
“Board”) authorized the issuance of Rights to purchase, on the terms and subject to the provisions of the Rights Agreement, shares of the Company’s Common Stock; 
 WHEREAS, on December 16, 1997, the Board (a) authorized and declared a dividend distribution of one Right for every share of Common Stock of
the Company outstanding at the Close of Business on the Dividend Record Date, and (b) authorized the issuance of, and agreed to issue, one Right (subject to certain adjustments) for every share of Common Stock of the Company issued between the
Dividend Record Date and the Distribution Date; and 
 WHEREAS, on December 30, 2005, pursuant to Section 27 of the Rights
Agreement, the Board approved an amendment of certain provisions of the Rights Agreement as set forth below; 
 NOW, THEREFORE, the Rights
Agreement is hereby amended as follows: 
 1. Amendment to Section 1(a). The definition of “Acquiring Person” in
Section 1(a) of the Rights Agreement is hereby amended by adding the following language between the existing clauses (iv) and (v), and renumbering existing clause (v) as clause (vi): 
 “(v) any Person who would otherwise become an Acquiring Person solely as a result of decreases in the outstanding number of shares of
Common Stock, provided that such Person does not thereafter purchase or otherwise acquire Beneficial Ownership of any additional shares” 
 2. Effectiveness. This Amendment shall be deemed effective as of the date first written above, as if executed on such date. Except as amended hereby, the Rights Agreement shall remain in full force and effect and shall be otherwise
unaffected hereby. 









 3. Miscellaneous. This Amendment shall be deemed to be a contract made under the laws of the State
of Delaware and for all purposes shall be governed by and construed in accordance with the laws of said State applicable to contracts to be made and performed entirely within said State. This Amendment may be executed in any number of counterparts
and each of such counterparts shall for all purposes be deemed to be an original, and all such counterparts shall together constitute but one and the same instrument. The invalidity or unenforceability of any term or provision hereof shall not
affect the validity or enforceability of any other term or provision hereof. If any term, provision, covenant or restriction of this Amendment is held by a court of competent jurisdiction or other authority to be invalid, void or unenforceable, the
remainder of the terms, provisions, covenants and restrictions of this Amendment shall remain in full force and effect and shall in no way be affected, impaired or invalidated. 
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 IN WITNESS WHEREOF, the parties hereto have caused this Amendment to the Rights Agreement to be duly
executed as of the day and year first above written. 
  

			
	 THE HANOVER INSURANCE GROUP, INC.

		
	By:	 	 /s/ Edward J. Parry

	 Name:
	 	 Edward J. Parry, III




			
	 Title:
	 	 Executive Vice President and
Chief Financial Officer



  

			
	 Attest:

		
	By:	 	 /s/ Charles F. Cronin

	 Name:
	 	 Charles F. Cronin



			
	 Title:
	 	 Vice President and Secretary


  

			
	 COMPUTERSHARE TRUST COMPANY, N.A.

		
	By:	 	  
	 Name:
	 	
	 Title:
	 	


  

			
	 Attest:

		
	By:	 	  
	 Name:
	 	
	 Title: