POWER OF ATTORNEY

Know all by these presents, that the undersigned hereby constitutes and appoints
Michael  H.  Gersie,  Karen E.  Shaff  and Joyce N.  Hoffman,  and each of them,
individually, the undersigned's true and lawful attorney-in-fact to:

(1)    execute  for  and on  behalf  of the  undersigned,  in the  undersigned's
       capacity as a  beneficial  owner of  securities  of  Principal  Financial
       Group,  Inc.  (the  "Company's"),  Schedules  13D  (including  amendments
       thereto)  and  Forms 3, 4 and 5 in  accordance  with  Section  13(d)  and
       Section 16(a),  respectively,  of the Securities Exchange Act of 1934 and
       the rules  thereunder  and any joint  filing  agreement  pursuant to Rule
       13d-1(k)(1)(iii);

(2)    do and  perform  any and all acts for and on  behalf  of the  undersigned
       which may be  necessary  or  desirable  to complete  and execute any such
       Schedule 13D (or amendment), Form 3, 4 or 5 or joint filing agreement and
       timely file such schedule or form with the United States  Securities  and
       Exchange Commission and any appropriate national securities exchange; and

(3)    take any  other  action of any type  whatsoever  in  connection  with the
       foregoing which, in the opinion of each 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 executed by each 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 he may approve in his discretion.

The undersigned hereby grants to each such attorney-in-fact  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, with full power of substitution or revocation,  hereby
ratifying and confirming all that each such attorney-in-fact,  or his 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 each such  attorney-in-fact  is serving in such  capacity at the request of
the  undersigned,  is not  assuming,  nor is the  Company  assuming,  any of the
undersigned's responsibilities to comply with Section 13(d) or Section 16 of the
Securities Exchange act of 1934.

The  Power  of  Attorney  shall  remain  in full  force  and  effect  until  the
undersigned is no longer  required to file  Schedules  13(d) or Forms 3, 4 and 5
with respect to the  undersigned's  holdings of and  transactions  in securities
issued by the Company,  unless  earlier  revoked by the  undersigned in a signed
writing delivered to each such attorney-in-fact.

From and after the date hereof, any Power of Attorney  previously granted by the
undersigned concerning the subject matter hereof is hereby revoked.

IN WITNESS  WHEREOF,  the  undersigned  has caused  this Power of Attorney to be
executed as of this 28th day of November, 2005.


                                               /S/ THERESE M. VAUGHAN
                                               ---------------------------------
                                               Name:  Therese M. Vaughan