<PAGE>

                                                                    Exhibit 10.1


                            UNITED STATES OF AMERICA
                                     BEFORE
              THE BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM
                                WASHINGTON, D.C.


------------------------------------)
                                    )
Written Agreement by and between    )
                                    )
CIVITAS BANKGROUP, INC.             )
Franklin, Tennessee                 )        Docket No. 05-011-WA/RB-HC
                                    )
and                                 )
                                    )
FEDERAL RESERVE BANK                )
  OF ATLANTA                        )
Atlanta, Georgia                    )
------------------------------------)


     WHEREAS, in recognition of their common goal to restore and maintain the
financial soundness of Civitas BankGroup, Inc., Franklin, Tennessee ("Civitas"),
a registered bank holding company that has or formerly had ownership interests
in, and provides operational oversight and services to, subsidiary banks (each
individually, a "Subsidiary Bank," and collectively, the "Subsidiary Banks"),
Civitas and the Federal Reserve Bank of Atlanta (the "Reserve Bank") have
mutually agreed to enter into this Written Agreement (the "Agreement");

     WHEREAS, Civitas oversees the activities and operations of the Subsidiary
Banks and services provided by Civitas to the Subsidiary Banks include but are
not limited to, risk management, credit administration, loan review, audit, and
deposit operations;

     WHEREAS, as a result of the identification of deficiencies in various areas
by the Reserve Bank, Civitas is taking steps to enhance and improve the
centralized functions and services it provides to the Subsidiary Banks; and

     WHEREAS, on April 21, 2005, the board of directors of Civitas, at a duly
constituted meeting, adopted a resolution authorizing and directing Richard
Herrington to enter into this


<PAGE>

Agreement on behalf of Civitas and consenting to compliance by Civitas and its
institution-affiliated parties, as defined in sections 3(u) and 8(b)(3) of the
Federal Deposit Insurance Act, as amended (the "FDI Act") (12 U.S.C. 1813(u) and
1818(b)(3)), with each and every applicable provision of this Agreement.

     NOW, THEREFORE, Civitas and the Reserve Bank agree as follows:

MANAGEMENT

     1.  (a) Within 30 days of this Agreement, the board of directors of Civitas
shall retain an independent consultant acceptable to the Reserve Bank to conduct
a review of the management, directorate, and organizational structure of Civitas
(the "Management Review") and to prepare a written report of findings and
recommendations (the "Consultant's Report"). The primary purpose of the
Management Review shall be to aid in the development of a directorate and
management structure, consisting of qualified and trained personnel, that is
suitable to Civitas's enterprise-wide needs. The Management Review shall, at a
minimum, address, consider, and include:

               (i) The identification of the type and number of officer
positions needed to manage and properly supervise the affairs of Civitas's
consolidated organization;

               (ii) the identification and establishment of committees of
Civitas's board of directors that are needed to provide guidance and oversight
for the consolidated organization;

               (iii) an evaluation of each Civitas officer and director to
determine whether the individual possesses the ability, experience, and other
qualifications required to competently perform present and anticipated duties,
including the ability to adhere to established policies and procedures of
Civitas; to restore Civitas to, and to thereafter maintain, a safe and


                                       2
<PAGE>

sound condition; and to comply with the requirements of this Agreement and all
applicable laws and regulations; and

               (iv) an evaluation of the information being provided to the board
of directors to enable it to carry out its responsibility to oversee the
operations and management of the consolidated organization.

         (b) Within 10 days of the engagement of the independent consultant, but
prior to the commencement of the Management Review, Civitas shall submit to the
Reserve Bank for approval an engagement letter that sets forth the scope of the
Management Review and the date of submission of the Consultant's Report, not to
exceed 90 days after the date of the Reserve Bank's approval of the engagement
letter.

         (c) Upon receipt of the Consultant's Report, Civitas shall forward a
copy to the Reserve Bank.

     2. Within 30 days of Civitas's receipt of the Consultant's Report, Civitas
shall submit to the Reserve Bank a written management plan that fully addresses
the findings and recommendations in the Consultant's Report and describes the
specific actions that the board of directors proposes to take in order to
strengthen Civitas's management and improve the board of directors' supervision
of Civitas. The plan shall, at a minimum, address, consider, and include actions
to improve and strengthen:

         (a) The consolidated organization's risk management program;

         (b) Civitas's oversight of the lending policies and procedures of the
Subsidiary Banks; and

         (c) Civitas's planning process and strategic direction.


                                       3
<PAGE>

INTERNAL AUDIT

     3. Within 60 days of this Agreement, Civitas shall submit to the Reserve
Bank an acceptable written plan to enhance the enterprise-wide internal audit
function. The plan shall address internal audit staffing in terms of the types,
number, and qualifications of staff needed to provide an effective audit program
for the organization in light of its size and complexity. The plan shall also at
a minimum, address, consider, and include:

         (a) Compliance with regulatory guidance regarding the internal audit
function, including but not limited to, the requirements of the Interagency
Policy Statement on the Internal Audit Function and its Outsourcing, issued
March 17, 2003;

         (b) establishment of an audit schedule that ensures that all areas,
including but not limited to, the Subsidiary Banks' wire transfer, teller
operations, lending, investment securities, and the organization's consolidated
balance sheet, and income and expenses, are audited at least yearly;

         (c) procedures for management to review audit reports quarterly,
formally respond in writing to criticisms in audit reports, and promptly
implement corrective actions that are responsive to audit findings;

         (d) procedures for tracking audit issues and the internal audit
function's review of management's corrective action; and

         (e) submission of quarterly audit reports and management responses to
the Audit Committee of the board of directors.

     4.  (a) Within 60 days of this Agreement, Civitas shall complete a review
of its enterprise-wide deposit operations. The purposes of the review shall be
to assess current internal controls over deposit operations and to make
findings, conclusions, and recommendations for



                                       4
<PAGE>

improvements to the internal controls, policies, and procedures in the area of
deposit operations. The review shall address, consider, and include, at a
minimum, the processes for issuing and controlling official checks, reactivating
dormant accounts, and controls over items held for customer pickup. Civitas
shall provide a copy of the findings, conclusions, and recommendations of the
review to the Reserve Bank upon completion.

         (b) Within 30 days of the completion of its review of Civitas's
enterprise-wide deposit operations, Civitas shall submit to the Reserve Bank an
acceptable written plan to strengthen deposit operations. The plan shall, at a
minimum, take into consideration the findings, conclusions, and recommendations
of the review completed pursuant to paragraph 4(a).

CREDIT ADMINISTRATION

     5. Within 60 days of this Agreement, Civitas shall submit to the Reserve
Bank an acceptable written plan to strengthen Civitas's enterprise-wide credit
administration policies, procedures, and practices. At a minimum, Civitas shall
ensure that its credit administration program includes:

         (a) Uniform underwriting standards for all new and renewed loans that
emphasize the importance of cash flow analysis of the borrower rather than
collateral-based lending and ensure that comprehensive financial statements, tax
returns, and other financial data indicating the borrower's capacity to repay
the loan are current at the time that the loan is extended are regularly updated
during the period that the loan remains outstanding;

         (b) procedures for exceptions to the loan policies, including required
documentation by the account officer and approval by each of the Subsidiary
Bank's board of



                                       5
<PAGE>

directors or committee, as appropriate, that each exception to the policies is
in the best interest of the Subsidiary Bank;

         (c) internal controls that are designed to ensure uniform adherence to
loan policies and procedures;

         (d) procedures for controlling and monitoring concentrations of credit,
including (i) establishing concentration of credit limits for acceptable
industries and types of loans; and (ii) managing the risk associated with asset
concentrations;

         (e) monthly reviews by Civitas's board of directors and senior
management of the level and trend of criticized assets (classified and special
mention loans) at each of the Subsidiary Banks, and the establishment of
benchmarks and timeframes for reducing the level of classified assets to
acceptable levels as determined by the board of directors and senior management;

         (f) collection policies and procedures that are designed to ensure that
the organization's consolidated past due and nonaccrual loan ratio remains at an
acceptable, manageable level as determined by Civitas's board of directors and
senior management; and

         (g) monthly reviews by Civitas's board of directors of the aggregate
dollar level and volume of all internally graded loans (grades 1 - 8), and all
past due and nonaccrual loans, as a percentage of total loans of each
wholly-owned Subsidiary Bank.

LOAN REVIEW

     6. Within 60 days of this Agreement, Civitas shall submit to the Reserve
Bank an acceptable enhanced independent loan review program. The program shall,
at a minimum, address, consider, and include the following:

         (a) The qualifications of the person or firm engaged to perform loan
reviews;



                                       6
<PAGE>

         (b) the periodic review of each loan in excess of $500,000 for
compliance with the original repayment schedule, verification of collateral
values and the Subsidiary Bank's interest in the collateral, the current
financial condition of the borrower and guarantor, and compliance with the
Subsidiary Bank's loan policy;

         (c) procedures to confirm the accuracy of all risk grades assigned by
loan officers;

         (d) monitoring and reporting of past due loans;

         (e) periodic reporting to the Subsidiary Bank's board of directors of
the status of the loan reviews and the action(s) taken by management to improve
the Subsidiary Bank's position on each adversely graded loan; and

         (f) documentation of any deviations from the recommendations made by
loan review in the minutes of the Subsidiary Bank's board of directors and
maintained for subsequent regulatory review.

CAPITAL PLAN

     7. (a) Within 90 days of this Agreement, Civitas shall submit to the
Reserve Bank an acceptable written plan to maintain a sufficient capital
position for the consolidated organization. The plan shall, at a minimum,
address, consider, and include:

               (i) The current and future capital requirements of each
wholly-owned Subsidiary Bank and the consolidated organization, including
compliance with the Capital Adequacy Guidelines for Bank Holding Companies:
Risk-Based Measure and Tier 1 Leverage Measure, Appendices A and D of Regulation
Y of the Board of Governors (12 C.F.R. Part 225, App. A and D);



                                       7
<PAGE>

               (ii) the asset quality, condition, and risk profile of each
wholly-owned Subsidiary Bank;

               (iii) the anticipated level of retained earnings and dividends of
each wholly-owned Subsidiary Bank and Civitas;

               (iv) actions to be taken and the source and timing of additional
funds to fulfill the consolidated organization's future capital requirements and
to maintain the adequacy of the consolidated organization's ALLL and each
wholly-owned Subsidiary Bank's ALLL; and

               (v) projected or anticipated growth of the consolidated
organization.

         (b) The board of directors shall monitor and review the sufficiency of
the consolidated organization's capital position on a quarterly basis and shall
reflect such reviews in the minutes of the meetings of the board of directors.

EARNINGS AND CASH FLOW

     8. Within 90 days of this Agreement, Civitas shall submit to the Reserve
Bank a written strategic plan that includes the goals and strategies for
improving consolidated earnings for a minimum of three years after the date of
this Agreement. The written plan shall, at a minimum, address, consider, and
include:

         (a) Identification of the major areas and means by which Civitas's
board of directors will seek to improve the operating performance of each
wholly-owned Subsidiary Bank;

         (b) financial performance objectives, including plans for asset growth,
earnings, liquidity, and capital supported by quarterly and annual pro forma
financial statements and assumptions; and

         (c) a budget review process that ensures, at a minimum:



                                       8
<PAGE>

               (i) Timely reporting of discrepancies between budget and
                   performance;

               (ii) documentation of variances from budget; and

               (iii) timely and appropriate revisions to budget.

     9. (a) Within 90 days of this Agreement, Civitas shall submit to the
Reserve Bank a comprehensive parent-only cash flow analysis detailing Civitas's
planned sources and uses of cash for debt retirement, operating expenses, and
other purposes for 2005.

         (b) For each year after 2005, Civitas shall by January 30 of such year
submit to the Reserve Bank a parent-only cash flow analysis for such year.

DIVIDENDS

     10. (a) Civitas shall not declare or pay any dividends, with the exception
of stock dividends, without the prior written approval of the Reserve Bank and
the Director of the Division of Banking Supervision and Regulation of the Board
of Governors.

         (b) Civitas shall not take dividends or any other form of payment
representing a reduction in capital from any wholly-owned Subsidiary Bank
without the prior written approval of the Reserve Bank.

         (c) All requests for prior approval shall be received by the Reserve
Bank at least 30 days prior to the proposed dividend declaration date and shall
contain, but not be limited to, current and projected information on
consolidated earnings, and cash flow, capital, asset quality, and loan loss
reserve needs of each wholly-owned Subsidiary Bank.

DEBT AND STOCK REDEMPTION

     11. (a) Civitas shall not, directly or indirectly, incur any debt without
the prior written approval of the Reserve Bank. All requests for prior written
approval shall be received by the Reserve Bank at least 30 days before the
company wishes to incur the indebtedness and



                                       9
<PAGE>

shall contain, at a minimum, a statement regarding the purpose of the debt, the
terms of the debt, the planned source(s) for debt repayment, and an analysis of
the cash flow resources available to meet such debt repayment. The foregoing
restrictions equally apply to any refinancing of existing indebtedness that
affect a change in materials terms of the debt instrument (e.g., interest rate,
maturity date, and amortization schedule).

         (b) Civitas shall not redeem any stock without the prior written
approval of the Reserve Bank.

COMPLIANCE WITH AGREEMENT

     12. (a) Within 30 days of this Agreement, the board of directors of Civitas
shall appoint a committee (the "Compliance Committee") to monitor and coordinate
the company's compliance with the provisions of this Agreement. The Compliance
Committee shall be comprised of three or more outside directors who are not
executive officers or principal shareholders, as defined in sections 215.2(e)(1)
and (m) of Regulation O of the Board of Governors (12 C.F.R. 215.2(e)(1) and
(m)), of Civitas or any of its subsidiaries or affiliates. At a minimum, the
Compliance Committee shall meet monthly, keep detailed minutes of each meeting,
and report to the boards of director on a monthly basis on the actions taken to
comply with this Agreement and the results of those actions.

         (b) Within 30 days after the end of each calendar quarter (June 30,
September 30, December 31, and March 31) following the date of this Agreement,
the board of directors of Civitas shall submit to the Reserve Bank written
progress reports detailing the form and manner of all actions taken to secure
compliance with this Agreement and the results thereof. Such reports may be
discontinued when the corrections required by this Agreement have been

                                       10
<PAGE>

accomplished and the Reserve Bank has, in writing, released Civitas from making
further reports.

APPROVAL OF PLANS, POLICIES, PROCEDURES, AND PROGRAMS

     13. The engagement letter, plans, and program required by paragraphs 1(b),
3, 4(b), 5, 6, and 7 of this Agreement shall be submitted to the Reserve Bank
for review and approval. An acceptable engagement letter, acceptable program,
and acceptable plans shall be submitted within the time periods set forth in
this Agreement. Civitas shall adopt the approved engagement letter, program, and
plans within 10 days of approval by the Reserve Bank and then shall fully comply
with them. During the term of this Agreement, the approved program and plans
shall not be amended or rescinded without the prior written approval of the
Reserve Bank.

COMMUNICATIONS

     14. All communications regarding this Agreement shall be sent to:

          (a)   Mr. Ron Zimmerman
                Vice President
                Federal Reserve Bank of Atlanta
                1000 Peachtree Street, N.E.
                Atlanta, Georgia 30309-4470

          (b)   Mr. Richard Herrington
                President and Chief Executive Officer
                Civitas BankGroup, Inc.
                810 Crescent Centre Drive, Suite 320
                Franklin, Tennessee 37067

MISCELLANEOUS

     15. Notwithstanding any provision of this Agreement to the contrary, the
Reserve Bank may, in its sole discretion, grant written extensions of time to
Civitas to comply with any provision of this Agreement.


                                       11
<PAGE>

     16. The provisions of this Agreement shall be binding upon Civitas and its
institution-affiliated parties, in their capacities as such, and their
successors and assigns.

     17. Each provision of this Agreement shall remain effective and enforceable
until formally stayed, modified, terminated or suspended in writing by the
Reserve Bank.

     18. The provisions of this Agreement shall not bar, estop, or otherwise
prevent the Board of Governors of the Federal Reserve System (the "Board of
Governors"), the Reserve Bank, or any other federal or state agency from taking
any other action affecting Civitas, the Subsidiary Banks, or any of their
current or former institution-affiliated parties and their successors and
assigns.

     19. This Agreement is a "written agreement" for the purposes of, and is
enforceable by the Board of Governors as an order issued under, section 8 of the
FDI Act (12 U.S.C. 1818).

     IN WITNESS WHEREOF, the parties have caused this Agreement to be executed
as of this 22nd day of April, 2005.


Civitas BankGroup, Inc.                     Federal Reserve Bank of Atlanta



By: /s/Richard Herrington                   By: /s/Ron Zimmerman
    ---------------------                       ----------------
    Richard Herrington                          Ron Zimmerman
    President                                   Vice President



                                       12