As filed with the Securities and Exchange Commission on June 19, 2015November 8, 2017

Registration No. 333-204088333 -            

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Amendment No. 2

to

FormS-4

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

FIRST FINANCIAL BANKSHARES, INC.

(Exact name of registrant as specified in its charter)

400 Pine Street

Abilene, Texas 79601

(325)627-7155

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

F. Scott Dueser

Chairman of the Board, President and Chief Executive Officer

First Financial Bankshares, Inc.

400 Pine Street

Abilene, Texas 79601

(325)627-7155

(325)627-7393 (Fax)

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale of the securities to the public: As soon as practicable after this registration statement becomes effective and all other conditions to the proposed merger described herein have been satisfied or waived.

If the securities being registered on this form are to be offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box: ¨☐

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:  ¨☐

If this form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:  ¨☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, anon-accelerated filer, or a smaller reporting company, or emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer” andfiler,” “smaller reporting company,” and “ emerging growth company” in Rule12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act .  ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Exchange Act Rule13e-4(i) (Cross-Border Issuer Tender Offer)  ☐

Exchange Act Rule14d-1(d) (Cross-Border Third-Party Tender Offer)  ☐

CALCULATION OF REGISTRATION FEE

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the registration statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

PRELIMINARY – SUBJECT TO COMPLETION, DATED NOVEMBER 8, 2017

The information in this proxy statement/prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This proxy statement/prospectus is not an offer to sell these securities, and it is not soliciting to buy these securities, in any state where the offer or sale is not permitted.

PRELIMINARY—SUBJECT TO COMPLETION, DATED JUNE 19, 2015

FBCPROXY STATEMENT/PROSPECTUS

COMMERCIAL BANCSHARES, INC.

PROPOSED MERGER—YOUR VOTE IS VERY IMPORTANT

Dear Shareholder:

You are cordially invited to attend the special meeting of shareholders of FBCCommercial Bancshares, Inc., referred to as FBC,“CBI”, to be held on July 23, 2015[    ] at 1:00[    ] p.m. at FBC’s office located at 1800 West White Oak Terrace, Conroe, Texas 77304.in the [    ]. At this important special meeting, you will be asked to approve the Agreement and Plan of Reorganization, dated April 1, 2015 (thewhich we refer to as the “reorganization agreement”), dated October 12, 2017, by and betweenamong First Financial Bankshares, Inc., referred to as First Financial, and FBC, which provides for the acquisition of FBC by First Financial. The acquisition of FBC by First Financial will be completed by means of a merger of FBC Acquisition Corp.“First Financial”, Kingwood Merger Sub, Inc., a wholly-owned subsidiary of First Financial referred to as “Merger Sub”, and CBI, which provides for the acquisition of CBI by First Financial. The acquisition of CBI by First Financial will be completed pursuant to the terms and conditions of the reorganization agreement by means of a merger of Merger Sub, with and into FBC, onCBI, which we refer to as the terms“merger”, with CBI surviving as a wholly-owned subsidiary of First Financial. Thereafter, First Financial will cause CBI to merge with and subjectinto First Financial, with First Financial surviving the merger, which together with the merger we refer to as the conditions contained in“integrated merger,” and subsequently, at such time that First Financial may determine, First Financial will cause Commercial State Bank to merge with and into First Financial Bank, N.A., with First Financial Bank, N.A. as the reorganization agreement. You may also be asked to adjourn or postpone the meeting to a later date or dates, if the board of directors of FBC determines it is necessary.surviving bank.

If the merger is completed, all outstanding shares of FBCCBI common stock, other than cancelled shares and dissenting shares, will be converted, pursuant to the reorganization agreement, into the right to receive a total number of shares of First Financial common stock with an expected aggregate value of approximately $59 million, subject to adjustment between a range of $57 million to $61 million of aggregate consideration based on the average price per share of First Financial’s common stock during the measurement period set forth in the reorganization agreement. Additionally, the aggregate consideration will be reduced on a dollar-for-dollar basis in the event that FBC’s consolidated shareholders’ equity, as calculated under the reorganization agreement, is less than $14,705,000 at closing. At the time of the shareholders meeting, FBC shareholders will not know the exact number of shares or the value of the First Financial common stock that will be issued in connection with the merger. Based on the closing price of First Financial common stock on June 17, 2015, shareholders of FBC would receive an aggregate$59.4 million. The number of shares of First Financial common stock equal todeliverable for each share of CBI common stock will be determined based on a volume-weighted average price of First Financial common stock over a measuring period for the twenty (20) consecutive trading days ending on the fifth business day immediately preceding the closing date of the merger. For illustration purposes only, using First Financial’s closing stock price of $44.40 on November 7, 2017 as a substitute for the volume-weighted average price, CBI stockholders would have received approximately 2.8%0.39 shares of First Financial common stock for each share of CBI common stock, which would have provided CBI stockholders with aggregate ownership of approximately 2.0% of the issued and outstanding shares of First Financial common stock after completion of the merger. First Financial’s common stock is listed on the NASDAQ Global Select Market under the symbol “FFIN.”We urge you to obtain current market quotations for First Financial’s common stock. There are no current market quotations for CBI common stock because CBI is a privately owned corporation and its common stock is not traded on any established public trading market.

In addition, in connection with the closing of the merger, CBI expects to pay a special dividend, referred to as the “special dividend”, to its shareholders of approximately $15.6 million in the aggregate, which may be increased or decreased for the amount by which CBI’s consolidated shareholders’ equity as of the closing date exceeds or is less than $42,402,486, after certain adjustments prescribed by the reorganization agreement for merger expenses. As of September 30, 2017, CBI’s shareholders’ equity was approximately $47.0 million. From September 30, 2017 through the anticipated closing of the merger in the first quarter of 2018, CBI estimates that it will earn approximately $1.3 million and that the exercise of outstanding stock options to purchase shares of CBI common stock will contribute an estimated additional $2.5 million to CBI’s consolidated shareholders’ equity. As of October 31, 2017, CBI estimated that its merger expenses, which will reduce CBI’s consolidated shareholders’ equity, would be approximately $1.1 million. Based on the foregoing estimates, CBI expects that the CBI shareholders will receive a special dividend of $6.56 in cash per share of CBI common stock in connection with the closing of the merger.

The board of directors of FBCCBI has determined that the reorganization agreement and the transactions contemplated therein, including the merger, are fair to and in the best interests of FBCCBI and its shareholders, and

approved and declared advisable the reorganization agreement and the transactions contemplated therein, including the merger.The FBCCBI board of directors recommends that you vote “FOR” the proposal to approve the reorganization agreement.

It is intendedFirst Financial and CBI intend that the transactions contemplated by the reorganization agreementmerger will be treated as reorganizationqualify for U.S. federal income tax purposes underas a reorganization within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended.

We cannot completeamended, which we refer to as the “Code”. If the merger unless we obtainqualifies as a reorganization under Section 368(a) of the necessary governmental approvalsCode, a U.S. holder (as defined in this proxy statement/prospectus) of CBI common stock who exchanges CBI common stock for a combination of First Financial common stock and cash should recognize gain (but not loss) in the exchange equal to the lesser of the cash received by such holder and the holdersamount, if any, by which the cash plus the fair market value of at least two-thirdsFirst Financial common stock received by such holder exceeds the tax basis of the outstandingsuch holder’s CBI common stock surrendered in exchange therefor (in each case excluding cash received in lieu of a fractional share of First Financial common stock). Further, a U.S. holder of CBI common stock generally will recognize gain or loss with respect to cash received in lieu of fractional shares of FBCFirst Financial common stock approvethat the reorganization agreement.U.S. holder would otherwise be entitled to receive.

Your vote is very important. Whetherimportant.Whether or not you plan to attend the special meeting, please take the time to vote by completing and mailing the enclosed proxy card to FBC.CBI. Submitting a proxy now will not prevent you from being able to vote in person at the special meeting. If you sign, date and mail your proxy card without indicating your vote, your proxy will be counted as a vote “FOR” the proposal to adopt and approve the reorganization agreement and the transactions contemplated thereby. If you do not return your proxy card, abstain from voting or do not instruct your brokerage firm, bank, trust or other nominee how to vote any shares held for you in “street name,” the effect will be a vote “AGAINST” such proposal.

This documentproxy statement/prospectus contains a more complete description of the special meeting, the reorganization agreement and the transactions contemplated therein, including the merger. We urge you to reviewPlease carefully read this entire document carefully.proxy statement/prospectus, including the“Risk Factors,” beginning on page 17, for a discussion of the risks relating to the proposed merger and an investment in First Financial common stock. You may also obtain information about First Financial from documents that First Financial has filed with the Securities and Exchange Commission, referred to as the “SEC.”

We thank you for your continued support and look forward to seeing you at the special meeting.

H.J. Shands, III

Chairman of the Board

FBC Bancshares, Inc.

Sincerely,

Harry J. Brooks

Chairman and Chief Executive Officer

CBI Bancshares, Inc.

An investment in First Financial common stock in connection with the merger involves risks. See“Risk Factors” beginning on page 16.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED THE MERGER OR OTHER TRANSACTIONS DESCRIBED IN THE ATTACHED PROXY STATEMENT/PROSPECTUS OR THE SECURITIES TO BE ISSUED PURSUANT TO THE MERGER UNDER THE ATTACHED PROXY STATEMENT/ PROSPECTUS NOR HAVE THEY DETERMINED IF THE ATTACHED PROXY STATEMENT/ PROSPECTUS IS ACCURATE OR ADEQUATE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

The securities that First Financial is offering through this document are not savings or deposit accounts or other obligations of any bank ornon-bank subsidiary of either of First Financial or FBC,CBI, and they are not insured by the Federal Deposit Insurance Corporation or any other governmental agency.

ProxyThe date of this proxy statement/prospectus dated June 19, 2015is [        ], 2017 and it is first being mailed to shareholders of FBCCBI on or about June 24, 2015.[        ], 2017

COMMERCIAL BANCSHARES, INC.

24080 Hwy 59 North, Suite 250

Kingwood, Texas 77339

(281)318-4555

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS

NOTICE IS HEREBY GIVEN that a special meeting of the shareholders of Commercial Bancshares, Inc., or CBI, will be held on [    ], 2017, at [    ] p.m., local time, at [    ], for the following purposes:

Only shareholders of record at the close of business on [    ], 2017 will be entitled to notice of and to vote at the special meeting and any adjournments or postponements thereof. Approval of the merger proposal requires the affirmative vote of the holders of at leasttwo-thirds of the outstanding shares of CBI common stock entitled to vote. The adjournment proposal requires the affirmative vote of a majority of the shares of CBI common stock present, in person or by proxy for approval. The special meeting may be adjourned or postponed from time to time upon approval of adjournment proposal by CBI’s shareholders without any notice other than by announcement at the meeting of the adjournment or postponement thereof, and any and all business for which notice is hereby given may be transacted at such adjourned or postponed meeting.

Shareholders of CBI have the right to dissent from the merger and obtain payment in cash of the appraised fair value of their shares of CBI common stock under applicable provisions of the Texas Business Organizations Code. In order for a shareholder of CBI to perfect its right to dissent, such shareholder must file a written objection to the merger prior to the special meeting, must vote against the merger proposal and must file a written demand with First Financial within 20 days after the consummation of the merger for payment of the fair value of the shareholder’s shares of CBI common stock. A copy of the applicable statutory provisions of the Texas Business Organizations Code is included asAppendix Eto the accompanying proxy statement/prospectus and a summary of these provisions can be found under the caption “Proposal 1: Merger Proposal —Dissenters’ Rights of CBI Shareholders.”

The board of directors of CBI unanimously recommends that you vote (i) “FOR” the merger proposal and (ii) FOR” the adjournment proposal.

Your Vote is Very Important.A proxy card is enclosed. Whether or not you plan to attend the special meeting, please complete, sign and date the proxy card and promptly mail it in the enclosed envelope. You may revoke your proxy card in the manner described in the proxy statement/prospectus at any time before the special meeting is called to order. If you attend the special meeting, you may vote in person if you wish, even if you have previously returned your proxy card.

This proxy statement/prospectus provides a detailed description of the CBI special meeting, the merger proposal, and the adjournment proposal, the documents related to the merger and other related matters. You are

urged to read this proxy statement/prospectus, including any documents they refer you to, and its annexes carefully and in their entirety. We look forward with pleasure to seeing and visiting with you at the special meeting.

By Order of the Board of Directors,

Harry J. Brooks

Chairman and Chief Executive Officer

Commercial Bancshares, Inc.

Kingwood, Texas

[    ], 2017

HOW TO OBTAIN ADDITIONAL INFORMATION

This proxy statement/prospectus incorporates important business and financial information about First Financial from documents filed with the SEC that have not been included in or delivered with this document. This information is described on page 6877 under “Where You Can Find More Information.” You can obtain free copies of this information by writing or calling:

First Financial Bankshares, Inc.

400 Pine Street

Abilene, Texas 79601

Attention: J. Bruce Hildebrand, Executive Vice President and Chief Financial Officer

Telephone(325) 627-7155

To obtain timely delivery of the documents before the special meeting of FBC,CBI, you must request the information by July 16, 2015.[        ], 2017.

PLEASE NOTE

We have not authorized anyone to provide you with any information other than the information included in this document and the documents to which we refer you. If someone provides you with other information, please do not rely on it as being authorized by us.

This proxy statement/prospectus has been prepared as of June 19, 2015.[            ], 2017. There may be changes in the affairs of FBCCBI or First Financial since that date, which are not reflected in this document.

ii

RISK FACTORS

In addition to general investment risks and the other information contained in or incorporated by reference into this proxy statement/prospectus, including the matters addressed under the section “A Warning About“Cautionary Statement Regarding Forward-Looking Statements” beginning on page 1921 and the matters discussed under the caption “Risk Factors” in Annual Report on Forms 10-K filed with the SEC by First Financial, for the year ended December 31, 2014,2016, as updated by other reports filed with the SEC, you should carefully consider the following risk factors in deciding how to vote on the proposals presented in this proxy statement/prospectus. See “Where You Can Find More Information” beginning on page 68.77.

Risks Relating to the Merger

The merger may not be completed.

Completion of the merger is subject to regulatory approval. First Financial cannot assure you that it will be successful in obtaining required regulatory approvals. If First Financial is not successful in obtaining required regulatory approvals, the merger will not be completed. If such regulatory approvals are received, there can be no assurance to the timing of those approvals or whether any conditions will be imposed that would result in certain closing conditions of the merger not being satisfied.

The consummation of the merger is also subject to other conditions precedent described in the reorganization agreement. If a condition of either party is not satisfied, the other party may be able to terminate the reorganization agreement and, in such case, the transaction would not be consummated. The parties cannot assure you that all of the conditions precedent in the reorganization agreement will be satisfied or that the merger will be completed.

The numbervalue of the shares of First Financial common stock received as merger consideration will fluctuate between the date the exchange ratio is determined (i.e., fifth business day immediately preceding the closing date of the merger) and the date shareholders of FBC mayCBI exchange their shares for the merger consideration.

If the merger is completed, all outstanding shares of CBI common stock, other than cancelled shares and dissenting shares, will be converted, pursuant to the reorganization agreement, into the right to receive more or lessa total number of shares of First Financial common stock with an aggregate value depending upon increasesof approximately $59.4 million. The number of shares of First Financial common stock deliverable for each share of CBI common stock will be determined based on a volume-weighted average price of First Financial common stock over a measuring period for the twenty (20) consecutive trading days ending on the fifth business day immediately preceding the closing date of the merger, rounded to the nearest cent, as reported by Bloomberg Finance L.P. Following the determination of the number of shares of First Financial common stock to be exchanged for each shares of CBI common stock, there will be a time period between such date and decreases in marketthe date that the stockholder receives the shares of First Financial common stock to be paid as merger consideration. During such time period, the price of First Financial’s common stock and the consolidated shareholders’ equity of FBC prior to closing.

The aggregate number of shares of First Financial stock issued to FBC shareholders in exchange for each share of FBC will fluctuate based upon changes in the market priceon a variety of First Financial’s common stock and the consolidated shareholders’ equity of FBC prior to the closing of the merger. The consolidated shareholders’ equity of FBC at the time the merger is completed may vary from the consolidated shareholders’ equity at the date the reorganization agreement was executed, the date of this document and at the date of the shareholders’ meeting of FBC.

Changes in the value of the merger consideration may be the result of various factors many of whichthat are beyond the control of First Financial, and FBC, including:

The merger may not be completed until a significant periodconditions, changes in First Financial’s business, operations and prospects and regulatory considerations. Accordingly, the actual aggregate value on the date that the CBI shareholders receive their shares of time has passed after the FBC’s shareholders’ meeting. At the time of the shareholder meeting, FBC shareholders will not know the exact number of shares or the value of the First Financial common stock that willmay be issued in connection with the merger.greater, equal to, or less than $59.4 million.

The market price of First Financial common stock after the merger may be affected by factors different from those affecting FBCCBI common stock or First Financial common stock currently.

The businesses of First Financial and FBCCBI differ in some respects and, accordingly, the results of operations of the combined company and the market price of First Financial’s shares of common stock after the merger may

be affected by factors different from those currently affecting the independent results of operations of each of First Financial and FBC.CBI. For a discussion of the business of First Financial and of certain factors to consider in connection with that business, see the documents incorporated by reference into this proxy statement/prospectus and referred to under “Where You Can Find More Information.”

Because CBI common stock is traded infrequently, it is difficult to determine how the fair value of CBI common stock compares with the merger consideration.

CBI common stock is not traded on any public markets. Any market for CBI common stock has been illiquid and irregular. This lack of liquidity makes it difficult to determine the fair value of CBI common stock.

The amount of the special dividend to be paid by CBI in connection with the closing of the merger may be an amount less than $15.6 million.

In connection with the closing of the merger, CBI expects to pay a special dividend to its shareholders of approximately $15.6 million in the aggregate; however, this amount will be increased or decreased for the amount by which CBI’s consolidated shareholders’ equity as of the closing date exceeds or is less than $42,402,486, after certain adjustments prescribed by the reorganization agreement for merger expenses. As of September 30, 2017, CBI’s shareholders’ equity was approximately $47.0 million. From September 30, 2017 through the anticipated closing of the merger in the first quarter of 2018, CBI estimates that it will earn approximately $1.3 million and that the exercise of outstanding stock options to purchase shares of CBI common stock will contribute an estimated additional $2.5 million to CBI’s consolidated shareholders’ equity. Preparing for integration of the merger may have a negative impact on CBI’s results of operations, and the merger-related expenses for which CBI will be liable are difficult to predict. As of October 31, 2017, CBI estimated that its merger expenses, which will reduce CBI’s consolidated shareholders’ equity, would be approximately $1.1 million. Based on such estimates, CBI expects to pay a special dividend of $6.56 per share. If CBI’s operations do not perform as expected or are negatively impacted by the merger, or if expenses associated with the merger are greater than expected, CBI may pay a special dividend less than $15.6 million. For a discussion of the possible downward adjustment to the cash component of the merger consideration, see “Proposal 1: Approval of the Merger Proposal—Terms of Merger—Merger Consideration” beginning on page 26.

Regulatory approvals may not be received, may take longer than expected or impose conditions that are not presently anticipated.

The Federal Reserve must approve First Financial’s acquisition of FBCCBI and the OCC must approve the merger of FirstCommercial State Bank with and into First Financial Bank. On April 10, 2015,October 20, 2017, First Financial filed an application with the Federal Reserve to obtain approval of the merger under the BHC Act and First Financial Bank and FirstCommercial State Bank filed an application with the OCC on October 18, 2017 to obtain approval of bank merger. First Financial received such approvals from the Federal Reserve and the OCC on May 20, 2015 and May 22, 2015, respectively. The Federal Reserve and the OCC considers,will consider, among other factors, the competitive impact of the merger, the financial and managerial resources of our companies and our subsidiary banks and the convenience and needs of the communities to be served. As part of that consideration, we expect that the Federal Reserve and OCC reviewedwill review issues related to capital position, safety and soundness, and legal and regulatory compliance, including compliance with anti-money laundering laws. There can be no assurance as to whether this and other regulatory approvals will be received, the timing of those approvals or whether any conditions will be imposed.

Shareholders should bear in mind that regulatory approval reflects only the view that the merger does not contravene applicable competitive standards imposed by law, and that the merger is consistent with regulatory policies relating to safety and soundness. Further, regulatory approval is not an opinion that the proposed merger is favorable to the shareholders of either party to the merger from a financial point of view or that the regulatory authority has considered the adequacy of the terms of the merger. Regulatory approval is not an endorsement or recommendation of the merger.

FBCCBI will be subject to business uncertainties while the merger is pending.

Uncertainty about the effect of the merger on employees and customers of FBCCBI may have an adverse effect on FBCCBI and its wholly-owned subsidiary, FirstCommercial State Bank, and consequently on First Financial following completion of the merger. These uncertainties may impair FBC’sCBI’s ability to attract, retain and motivate key

personnel until the merger is completed, and could cause customers and others that deal with FBCCBI to seek to change existing business relationships with FBC.CBI. Retention of certain employees of FBCCBI and FirstCommercial State Bank may be challenging while the merger is pending, as certain employees may experience uncertainty about their future roles with First Financial. If key employees depart, First Financial’s business following the merger could be harmed. See the section entitled “Proposal 1: Approval of the Reorganization Agreement—Merger Proposal—Conduct of Business Pending Effective Time” beginning on page 3543 of this proxy statement/prospectus for a description of the restrictive covenants to which FBCCBI is subject.

Combining our two banks may be more difficult, costly or time-consuming than we expect.

First Financial Bank and FirstCommercial State Bank have historically operated and, until the bank merger is completed, will continue to operate, independently. It is possible that the integration process could result in the loss of key employees or disruption of each bank’s ongoing business or inconsistencies in standards, controls, procedures and policies that adversely affect our ability to maintain relationships with customers and employees or to achieve the anticipated benefits of the merger. As with any combination of banking institutions, there also may be business disruptions that cause us to lose customers or cause customers to take their deposits out of our banks. The success of the combined bank following the merger may depend in large part on the ability to integrate the two businesses, business models and cultures. If we are not able to integrate our operations successfully and timely, the expected benefits of the merger may not be realized.

Some of the directors and officers of FBCCBI may have interests and arrangements that may have influenced their decisions to support or recommend that you approve the reorganization agreementmerger proposal and the transactions contemplated therein.

The interests ofCBI’s shareholders should be aware that some of theCBI’s directors and officers of FBC may be different from those of FBC shareholders, and such directors andexecutive officers may be participantshave interests in the merger and have arrangements that are different from, or in addition to, those of FBC shareholders.CBI’s shareholders generally. The board of directors of CBI was aware of these interests and considered these interests, among other matters, when making its decision to approve the reorganization agreement, and in recommending that CBI’s shareholders vote in favor of approving the merger proposal. These interests are describedinclude the following:

For a more detail in the sectioncomplete description of this proxy statement/prospectus entitled “Proposal 1: Approvalthese interests, see “The Merger—Interests of the Reorganization Agreement—Financial Interests ofCBI’s Directors and Officers of FBC in the Merger”beginning on page 43.50.

First Financial may fail to realize the cost savings estimated for the merger.

Although First Financial estimates that it will realize cost savings from the merger when integrated, it is possible that the estimates of the potential cost savings could turn out to be incorrect. For example, the combined purchasing power may not be as strong as expected, and therefore the cost savings could be reduced. In addition, unanticipated growth in First Financial’s business may require First Financial to continue to operate or maintain some facilities or support functions that are currently expected to be combined or reduced. The cost savings estimates also depend on our ability to combine the businesses of First Financial Bank and FirstCommercial State Bank in a manner that permits those costs savings to be realized. If the estimates turn out to be incorrect or First Financial is not able to combine successfully the two banks, the anticipated cost savings may not be fully realized or realized at all, or may take longer to realize than expected.

FBCCBI shareholders will have a reduced ownership and voting interest after the merger and will exercise less influence over management.

The merger will transfer control of FBCCBI to First Financial and to the shareholders of First Financial. When the merger is completed, each FBCCBI shareholder (other than dissenting shareholders) will become a shareholder of First Financial with a percentage ownership of First Financial much smaller than such shareholder’s percentage ownership of FBC.CBI. Because of this, FBCCBI shareholders will have less influence on the management and policies of First Financial, and thus First Financial Bank, than they now have on the management and policies of FBC.

If the merger is not completed, First Financial and CBI will have incurred substantial expenses without realizing the expected benefits of the merger.

Each of First Financial and CBI has incurred and will incur substantial expenses in connection with the negotiation and completion of the transactions contemplated by the reorganization agreement, as well as the costs and expenses of filing, printing and mailing this proxy statement/prospectus and all filing and other fees paid to the SEC in connection with the merger. If the merger is not completed, First Financial and CBI would have to recognize these expenses without realizing the expected benefits of the merger.

The opinion of CBI’s financial advisors received by the board of directors of CBI prior to the signing of the reorganization agreement does not reflect changes in circumstances since the date of such opinion.

The opinion of CBI’s financial advisor received by the board of directors of CBI was delivered on September 26, 2017. Changes in the operations and prospects of First Financial or CBI, general market and economic conditions and other factors that may be beyond the control of First Financial or CBI may significantly alter the value of CBI or the price of First Financial’s common stock by the time the merger is completed. The opinion speaks only as of the date of such opinion and not as of the date of this proxy statement/prospectus, the time the merger will be completed or as of any date other than the date of such opinion.

Litigation may be filed against First Financial, CBI or their respective boards of directors or officers, which could prevent or delay the completion of the merger or result in the payment of damages following completion of the merger.

Lawsuits may be filed against First Financial, CBI or their respective boards of directors or officers in connection with the merger, which could prevent or delay completion of the merger and result in substantial costs to First Financial and CBI, including any costs associated with indemnification. The defense or settlement of any lawsuit or claim that remains unresolved at the time the merger is completed may adversely affect First Financial’s and CBI’s business, financial condition, results of operations and cash flows following completion of the merger.

A WARNING ABOUT FORWARD-LOOKING STATEMENTS

Certain statements contained in this proxy statement/prospectus, including statements included or incorporated by reference in this proxy statement/prospectus, that are not statements of historical fact constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to risks and uncertainties. These forward-looking statements include information about possible or assumed future results of operations of First Financial after the merger is completed as well as information about the merger. Words such as “believes,” “expects,” “anticipates,” “estimates,” “intends,” “continue,” “should,” “may,” or similar expressions, or the negatives thereof, are intended to identify forward-looking statements, but are not the exclusive means of identifying such statements. Many possible events or factors could affect the future financial results and performance of each of our companies before the merger or First Financial after the merger, and could cause those results or performance to differ materially from those expressed in the forward-looking statements. These possible events or factors include, but are not limited to:

For other factors, risks and uncertainties that could cause actual results to differ materially from estimates and projections contained in forward-looking statements, please read the “Risk Factors” section of this proxy statement/prospectus.

A forward-looking statement may include a statement of the assumptions or bases underlying the forward-looking statement. We believe we have chosen these assumptions or bases in good faith and that they are

reasonable. However, we caution you that assumptions or bases almost always vary from actual results, and the differences between assumptions or bases and actual results can be material. Therefore, we caution you not to place undue reliance on our forward-looking statements. The forward-looking statements are made as of the date of this proxy statement/prospectus or the date of the applicable document incorporated by reference into this proxy statement/prospectus. We undertake no obligation to publicly update or otherwise revise any forward-looking statements, whether as a result of new information, future events or otherwise.

GENERAL INFORMATION

This document constitutes a proxy statement of FBCCBI and is being furnished to all record holders of FBCCBI common stock in connection with the solicitation of proxies by the board of directors of FBCCBI to be used at the special meeting of shareholders of FBCCBI to be held on July 23, 2015.[            ], 2017. The purpose of the FBCCBI special meeting is to consider and vote to approve the reorganization agreement, dated April 1, 2015, by and between First Financial and FBC, and the transactions contemplated by the reorganization agreement including, among other things, the merger of FBC Acquisition Corp.,a wholly-owned subsidiary of First Financial, with and into FBC, with FBC surviving the merger as a wholly-owned subsidiary of First Financial.proposal.

This document also constitutes a prospectus relating to the First Financial common stock to be issued to shareholders of FBCCBI common stock upon completion of the merger.

FBCCBI SPECIAL SHAREHOLDERS’ MEETING

Date, Place and Time of the Special Meeting

The special meeting of shareholders of FBCCBI will be held on July 23, 2015[            ], 2017 at 1:00 p.m.,[            ], local time, at FBC’s office located at 1800 West White Oak Terrace, Conroe, Texas 77304.[            ]. The special meeting may be postponed to another date or place for proper purposes, including for the purpose of soliciting additional proxies.

Purpose

The purpose of the special meeting are to consider and vote on the following:

At this time, the board of directors of FBCCBI and the voting representatives are unaware of any matter, other than the matter set forth above, that may be presented for action at the special meeting.

Record Date; Shares Entitled to Vote

The close of business on June 19, 2015[            ], 2017 is the record date. The holders of record of the outstanding shares of FBCCBI common stock as of the close of business on the record date are entitled to notice of, and to vote at, the special meeting, or any postponement thereof. At the close of business on the record date, there were 884,600[    ] shares of FBCCBI common stock outstanding and entitled to vote at the special meeting. At the special meeting, the shareholders of FBCCBI will be entitled to one vote for each share of common stock owned as of the close of business on the record date.

Quorum; Vote Required

The holders of a majority of the shares of FBCCBI common stock entitled to vote at the special meeting must be present, either in person or by proxy, to constitute a quorum at the special meeting. Approval of the reorganization agreementmerger proposal requires the affirmative vote of the holders of at least two-thirds of the outstanding shares of FBCCBI common stock entitled to vote. If you fail to vote, it will have the effect of a vote against the reorganization agreement.merger proposal.

Shares Held by Directors and Named Executive Officers

As of the record date, all of the directors of FBC (5 persons)CBI and named executive officers of FBCCBI were entitled to vote 232,051697,845 shares of FBCCBI common stock, or approximately 26.2%20.6% of the outstanding shares of the common stock

entitled to vote at the special meeting. Each of the directors and executive officers has executed a Voting Agreement, and Irrevocable Proxy, dated as of April 1, 2015,October 12, 2017, referred to as the “voting agreement” in this proxy statement/prospectus, pursuant to which each director and executive officer agreed to vote his shares of FBCCBI common stock in favor of approval of the merger pursuant to the reorganization agreement. In addition to the directors, certain shareholders of FBC have entered into the voting agreement. As of the record date, 714,098737,556 shares of FBCCBI common stock, or approximately 80.7%21.8% of the outstanding shares of FBCCBI common stock entitled to vote at the FBCCBI special meeting, are bound by the voting agreement. Accordingly, approval

The foregoing description of the merger pursuantvoting agreement is subject to, and qualified in its entirety by reference to, the reorganizationvoting agreement, a form of which is attached to this proxy statement/prospectus asAppendix B and is incorporated by the FBC shareholders is assumed.reference into this proxy statement/prospectus.

Voting and Revocation of Proxies

Any holder of record of shares of FBCCBI common stock entitled to vote may submit a proxy by returning a signed proxy card by mail, or may vote in person by appearing at the special meeting. Proxies, in the form enclosed, which are properly executed and returned to FBCCBI and not subsequently revoked, will be voted in accordance with the instructions indicated on the proxies. Any properly executed proxy on which voting instructions are not specified will be voted “FOR the proposal to approve” the merger pursuant toproposal and “FOR” the reorganization agreement.adjournment proposal The proxy also grants authority to the persons designated in such proxy to vote in accordance with their own judgment if an unscheduled matter is properly brought before the special meeting.

If you are a beneficial owner and hold your shares of FBCCBI common stock in “street name” through a brokerage firm, bank, trust or other nominee, you should instruct your nominee on how you wish to vote your shares of FBCCBI common stock using the instructions provided by your nominee. Under applicable rules, brokerage firms, banks, trusts and other nominees have the discretion to vote on routine matters. The merger proposal is a non-routine matter, and brokerage firms, banks, trusts and other nominees cannot vote on these proposals without your instructions. Therefore, it is important that you cast your vote or instruct your brokerage firm, bank, trust or other nominee on how you wish to vote your shares of FBCCBI common stock.

If you do not return your proxy card or attend the special meeting, your shares of FBCCBI common stock will not be voted, which will have the same effect as a vote against the merger. Even if you plan to attend the special meeting, if you hold your shares of FBCCBI common stock in your own name as the shareholder of record, please vote your shares of FBCCBI common stock by completing, signing, dating and returning the enclosed proxy card.

If you are the record holder of your shares, you may revoke any proxy given pursuant to this solicitation by the board of directors of FBCCBI at any time before it is voted at the special meeting by:

All written notices of revocation and other communications with respect to revocation or proxies must be received by FBCCBI no later than July 22, 2015,[            ], 2017, at 5:00 p.m. local time, which is the business day immediately prior to the special meeting and should be sent to: FBCCommercial Bancshares, Inc., 1800 West White Oak Terrace, Conroe,24080 Hwy 59 North, Suite 250, Kingwood, Texas 77304,77339, Attention: Secretary. If you hold your shares in street name with a brokerage firm, bank, trust or other nominee, you must contact such brokerage firm, bank, trust or other nominee if you wish to revoke your proxy.

Your presence without voting at the special meeting will not automatically revoke your proxy, and any revocation during the special meeting will not affect votes previously taken.

The secretary of FBCCBI will determine all questions as to validity, form, eligibility (including time of receipt) and acceptance of proxies. Its determination will be final and binding. The board of directors has the right to waive any irregularities or conditions as to the manner of voting. FBCCBI may accept your proxy by any form of communication permitted by the TBOC so long as FBCCBI is reasonably assured that the communication is authorized by you.

Shares Held in Street Name

Your brokerage firm, bank, trust or other nominee cannot vote your shares of FBCCBI common stock for or against approval and adoption of the merger proposal unless you tell the brokerage firm, bank, trust or other nominee how you wish to vote. To tell your nominee how to vote, you should follow the directions that your nominee provides to you. Please note that you may not vote your shares of FBCCBI common stock held in “street name” by returning a proxy card directly to FBCCBI or by voting in person at the special meeting unless you provide a “legal proxy,” which you must obtain from your nominee. If you do not instruct your broker or other nominee on how to vote your shares of FBCCBI common stock, your broker or other nominee may not vote your FBCCBI common shares, which will have the same effect as a vote against the merger proposal for purposes of the required vote. You should therefore provide your brokerage firm, bank, trust or other nominee with instructions as to how to vote your shares of FBCCBI common stock.

Solicitation of Proxies; Expenses

This proxy solicitation is made by the board of directors of FBC. FBCCBI. CBI is responsible for its expenses incurred in preparing, assembling, printing and mailing this proxy statement/prospectus. Proxies will be solicited through the mail. Additionally, directors of FBCCBI intend to solicit proxies personally or by telephone or other means of communication. The directors will not be additionally compensated. FBCCBI will reimburse banks, brokers and other custodians, nominees and fiduciaries for their reasonable expenses in forwarding the proxy materials to beneficial owners.

Recommendation of FBC’sCBI’s Board of Directors

After considering various factors described in the section entitled “Proposal 1: Approval of the Reorganization Agreement—Merger Proposal—Recommendation of FBC’s BoardCBI’s board of Directorsdirectors and its Reasons for the Merger,” the board of directors of FBCCBI has unanimously determined that the reorganization agreement and the transactions contemplated by the reorganization agreement, including the merger, are advisable and in the best interests of FBC’sCBI’s shareholders and has adopted and approved the reorganization agreement and the transactions contemplated by the reorganization agreement, including the merger. The board of directors recommends that you vote “FOR” the proposal to adopt and approve the reorganization agreement.merger proposal.

Dissenters’ Rights

Holders of shares of FBCCBI common stock are entitled to dissenters’ rights under Subchapter H of Chapter 10 of the TBOC, provided they satisfy the special conditions and conditions set forth therein. For a more detailed discussion of your dissenters’ rights and the requirements for perfecting your dissenters’ rights, see “Proposal 1: Approval of the Reorganization Agreement—Merger Proposal—Dissenters’ Rights of FBCCBI Shareholders” on page 50.59. In addition, a copy of Subchapter H of Chapter 10 of the TBOC is attached as Annex C to this proxy statement/prospectus.

PROPOSAL 1: APPROVAL OF THE REORGANIZATION AGREEMENTMERGER PROPOSAL

The following information describes material aspects of the merger pursuant to the reorganization agreement. It is not intended to be a complete description of all information relating to the merger pursuant to the reorganization agreement and is qualified in its entirety by reference to more detailed information contained in the appendices to this document, including the reorganization agreement. A copy of the reorganization agreement is included asAppendix A and is incorporated herein by reference. You are urged to read the appendices in their entirety.

Terms of the Merger

Structure of Merger. The.The reorganization agreement provides for the acquisition of FBCCBI and its wholly-owned subsidiary, FirstCommercial State Bank, by First Financial. If (i) the shareholders of FBCCBI approve the merger pursuant to the reorganization agreementproposal at the special meeting, (ii) the required regulatory approvals are obtained, and (iii) the other conditions to the parties’ obligations to effect the transactions contemplated by the reorganization agreement are met or waived by the party entitled to do so, we anticipate that the transactions contemplated by the reorganization agreement will be completed in July 2015,the first quarter of 2018, although delays could occur.

The first transaction contemplated by the reorganization agreements is the merger of FBC Acquisition Corp.,Merger Sub, a wholly-owned transitory subsidiary of First Financial, with and into FBC,CBI, with FBCCBI surviving the merger as a wholly-owned subsidiary of First Financial. As a result of the merger, holders of FBCCBI common stock as of the effective time of the merger, other than canceled shares and dissenting shares, will be entitled to receive whole shares of First Financial common stock and in some instances, cash, with additional cash payable in lieu of any fractional share. Following the merger, certificates for FBCCBI common stock will only represent the right to receive the merger consideration pursuant to the reorganization agreement, and otherwise will be null and void.

Following immediately after the merger, or at such later time as First Financial may determine in its sole discretion, First Financial will cause (i) FBCCBI to merge with and into First Financial, with First Financial as the surviving entity and FBCCBI ceasing its separate corporate existence and (ii) FirstCommercial State Bank to merge with and into First Financial Bank, with First Financial Bank as the surviving bank and FirstCommercial State Bank ceasing its separate corporate existence. As a result of the bank merger, the existing branches and main office of FirstCommercial State Bank will become branches of First Financial Bank.

Merger Consideration. If the merger is completed, all outstanding shares of CBI common stock, other than cancelled shares and dissenting shares, will be converted, pursuant to the reorganization agreement, into the right to receive a total number of shares of First Financial common stock with an aggregate value of approximately $59.4 million. The number of shares of First Financial common stock deliverable for each share of FBCCBI common stock will be determined based on thea volume-weighted average daily closing price of First Financial’sFinancial common stock onover a measuring period for the NASDAQ Global Select Market for each of the twenty (20) consecutive trading days ending on the fifth business day immediately preceding the closing date of the merger, referred to as the “FFIN Market Price” in this proxy statement/prospectus. Subjectrounded to the terms of the reorganization agreement, the general method for calculating the number of shares to be issued for each share of FBC common stock is to divide the aggregate merger considerationnearest cent, as reported by (i) the number of shares of FBC common stock outstanding, less certain adjustments and (ii) the FFIN Market Price. Subject to the adjustments set forth in the reorganization agreement, the aggregate merger consideration will be determined as follows:

for each share of FBC common stock, which would have provided FBC for each share of CBI common stock, which would have provided CBI stockholders with aggregate ownership, on a pro forma basis, of approximately 2.8% of the common stock of First Financial following the merger.;

Regardlessownership of approximately 2.0% of the FFIN Market Price, the maximum number ofissued and outstanding shares of First Financial common stock that First Financial is required to issue underafter completion of the reorganization agreement is 2,231,941 shares of First Financial common stock (the “FFIN Share Cap”). To the extent that the aggregate merger consideration due to the holders of FBC common stock pursuant to the reorganization agreement exceeds the value of shares of First Financial common stock equal to the FFIN Share Cap, First Financial may, in its sole discretion, (i) increase(based on the number of shares of First FinancialFinancial’s common stock issued in excess of the FFIN Share Cap, (ii) increase the number of shares of First Financial common stock issued in excess of the FFIN Share Cap and pay an additional cash amount, or (iii) pay an additional cash amount.

Consideration Examples. The following table, which is for illustration purposes only, provides examples of the consideration that would be payable to holders of FBC common stock based upon the FFIN Market Prices listed in the table. The table does not reflect all possible adjustments that may be made to the merger consideration that are set forth in the reorganization agreement including, without limitation, possible adjustments for the consolidated shareholders’ equity or that cash will be paid instead of fractional shares. The following table assumes that 884,600 shares of FBC common stock will be outstanding as of November 7, 2017).

In addition, in connection with the effective timeclosing of the merger. The actual prices at which First Financial common stock trades will establish the actual FFIN Market Price. The actual trading pricemerger, CBI expects to pay a special dividend to its shareholders of First Financial common stock is subject to market fluctuations.

Downward Adjustment of Consideration. The aggregate merger consideration to be paid pursuant to the reorganization agreement will be reduced on a dollar-for-dollar basisapproximately $15.6 million in the event that FBC’saggregate, which may be increased or decreased for the amount by which CBI’s consolidated shareholders’ equity as of the close of business on the business day immediately preceding the closing date of the merger,exceeds or is less than $42,402,486, after certain adjustments prescribed by the reorganization agreement have been made, is less than $14,705,000.

Dividendfor merger expenses. Pursuant to the terms of Excess Shareholders’ Equity. To the extent that FBC’sreorganization agreement, CBI’s consolidated shareholders’ equity may be reduced for the

following merger expenses, among others, (i) the legal, professional, investment banking, consulting and accounting fees and expenses of CBI associated with the merger, including any cost to obtain any opinion as ofto the close of business on the business day immediately preceding the closing datefinancial fairness of the merger, after(ii) all fees related to obtaining the tail insurance for CBI’s and Commercial State Bank’s officers and directors, (iii) the payments owed by CBI or Commercial State Bank for anystay-pay or retention bonus amounts (other thanstay-pay or retention bonus amounts requested or directed by First Financial) or change in control payments, (iv) the cost of terminating any employment related agreements and obligations (including anynon-competition agreements, option agreements or equity based plans) including, among others, the employment agreements and certain adjustments prescribedsurvivor income agreements, (v) if requested by First Financial, a mutually agreeable estimate of the cost of obtaining a determination letter from the Internal Revenue Service in connection with the termination of a retirement plan, (vi) any federal income tax obligations, franchise tax obligations or real property tax obligations incurred prior to the effective time of the merger, (vii) the accrual or payment of all of the costs, fees, expenses and penalties necessary to be paid by CBI or Commercial State Bank in connection with any contract termination required pursuant to the reorganization agreement, including, without limitation, all costs, fees, expenses and penalties associated with the termination of the data processing or technology contracts or other contracts contemplated by the reorganization agreement, have been made, exceeds $14,705,000, FBC may dividendand (viii) a reduction in the excess amount to its shareholders prior to closing.

Debt Repayment. First Financial has also agreed to redeem all of FBC’s Subordinated Promissory Notes due June 30, 2028 within three business days of the total consolidated shareholders’ equity of CBI equal to the amount of the gain recognized on the property located at 29818 FM 1093, Fulshear, Ft. Bend County, Texas.

As of September 30, 2017, CBI’s shareholders’ equity was approximately $47.0 million. From September 30, 2017 through the anticipated closing dateof the merger in the first quarter of 2018, CBI estimates that it will earn approximately $1.3 million and that the exercise of outstanding stock options to purchase shares of CBI common stock will contribute an estimated additional $2.5 million to CBI’s consolidated shareholders’ equity. As of October 31, 2017, CBI estimated that its merger expenses, which will reduce CBI’s consolidated shareholders’ equity, would be approximately $1.1 million. Based on the foregoing estimates, CBI expects that the CBI shareholders will receive a special dividend of $6.56 in cash per share of CBI common stock in connection with the closing of the merger. The Subordinated Promissory Notes due June 30, 2028 had an aggregate outstanding principal balance of $13,125,000If CBI’s operations do not perform as of April 1, 2015.expected or are negatively impacted by the merger, or if expenses associated with the merger are greater than expected, CBI may pay a special dividend less than $15.6 million.

The actual merger consideration is subject to adjustment and may be higher or lower than the consideration described in the examples above. Because the per share merger considerationamount of the special dividend will be determined based upon the price of First Financial’s common stock and the adjusted consolidated shareholders’ equity of FBC,CBI, the amount of consideration you will receive will not be known at the time you vote on the reorganization agreement. Accordingly, you should read this proxy statement/prospectus carefully to understand the value of the consideration you will receive in the merger.

Background of the Merger

The FBC board of directors periodically has reviewed FBC’s performance, compared its performance with thatand management of certain comparable institutions, reviewedCBI regularly review CBI’s future prospects for earnings and asset growth as well as the limited market activity in FBC’s common stock, considered various business opportunitiesimplementation and strategies availableviability of CBI’s strategic initiatives. From time to FBC and discussedtime, the general economic, regulatory, competitive and business pressures affecting FBC and First Bank. In addition, the FBC board of directors on an informal basis and during strategic planning sessions, would periodically review mergermanagement reviewed and acquisition activitydiscussed CBI’s long-term objectives and considered ways in which it could enhance shareholder value as well as its performance, and discussed and evaluated, among other things, the banking industry.economic and regulatory environment in general and for South Texas in addition to financial institutions, specifically.

In November 2012, F. Scott Dueser,Over the past few years, representatives from Hovde Group, LLC have met with and assisted Harry J. “Johnny” Brooks, Chairman, of the Board, President and Chief Executive Officer of CBI with evaluating strategic options available to CBI. As part of these discussions, Mr. Brooks and Hovde have evaluated both acquisitions for CBI as well as strategic merger partners for CBI, as well as other strategic options available to CBI such as capital raising options. Furthermore, and during these discussions, Mr. Brooks discussed with Hovde the desire for shareholder liquidity and the ability for CBI to merge with another institution that would both enhance shareholder value while also providing cash and or a marketable stock as form of consideration.

During September 2016, Mr. Brooks was approached, on an unsolicited basis, by representatives of Bank A about the potential for Bank A to acquire CBI. During these discussions, the CEO of Bank A noted orally Bank A’s interest in acquiring CBI for $70 million in cash. After the meeting, Mr. Brooks made Hovde aware of this proposal and decided to schedule afollow-up meeting with Bank A to discuss what a transaction might look like. Afollow-up meeting between Mr. Brooks and representatives of Bank A occurred on September 29, 2016. During this meeting executives from Bank A indicated that they would be prepared to increase theirall-cash offer to between $72 million and $75 million. Mr. Brooks indicated that if Bank A would deliver this offer in writing he would call a special meeting to discuss the offer with CBI’s board of directors. Shortly after this meeting, Bank A indicated that, for various reasons regarding Bank A, it were no longer in a position to pursue a transaction with CBI and discussions terminated.

As part of these discussions, Mr. Brooks and Hovde discussed the timing of a transaction due to, among other things, a favorable market for pursuing a merger as well as favorable termination costs associated with CBI’s major service providers. On September 14, 2016, representatives from Hovde visited with Scott Dueser, Chairman, President and CEO of First Financial in Austin, Texas. During this visit, Mr. Dueser noted to Hovde First Financial’s interest in expanding around the Houston, Texas market. After the visit, Hovde relayed this interest to Mr. Brooks and Mr. Brooks indicated that he thought highly of First Financial as a company and would be interested in visiting with representatives of First Financial if the interest was mutual. Hovde then contacted Sam W. Baker, President of FBC and President and Chief Executive Officer of the First Bank, by telephoneMr. Dueser to preliminarily discussset up a possible business combinationmeeting between First Financial and CBI. This meeting occurred on December 16, 2016 in Kingwood, Texas. After the visit, First Bank (FBC had not been formedFinancial declined to pursue a deal at that time). Messrs.time but indicated its interest in CBI and agreed to continue discussions.

Mr. Dueser contacted Mr. Brooks in early January 2017 and Baker spoke againinvited him to meet in Abilene, Texas on January 12, 2017. At that meeting, Mr. Dueser made an oral offer to acquire CBI for $60 million. Mr. Brooks responded that he knew that would not be acceptable to the CBI board of directors or shareholders. The discussions terminated at that point.

In April 2017, Mr. Brooks was contacted, on an unsolicited basis, by telephonethe Chairman of Bank B to indicate Bank B’s interest in pursuing a transaction with CBI. Mr. Brooks relayed this interest and conversation to Hovde, and, after conferring, decided that Bank B was a strong candidate and Mr. Brooks continued discussions. On April 13, 2017 Bank B invited Mr. Brooks to its headquarters to visit in person and discuss the details of a potential merger between CBI and Bank B. After this meeting, the Chairman of Bank B indicated Bank B’s interest in providing CBI with an indication of interest (“IOI”) to detail the terms for which Bank B would propose acquiring CBI.

On May 25, 2017, Bank B provided anon-binding IOI to Mr. Brooks outlining the proposed transaction between Bank B and CBI. The terms within the IOI detailed an offer for CBI based on $69 millionall-cash offer. Mr. Brooks then met with members of CBI’s executive committee to discuss the terms outlined within the IOI. After visiting with the executive committee, it was determined that the proposed offer from Bank B was inadequate in order to relinquish independence and sell CBI. Mr. Brooks responded to Bank B that an offer of $75 million was needed based on CBI’s tangible common equity as of March 31, 2017. Bank B responded that it would need additional due diligence before responding to CBI.

During May 2017 and June 20132017, Mr. Brooks worked with Hovde to provide Bank B additional due diligence and projections for CBI. On May 31, 2017, Hovde was formally engaged to represent CBI as its exclusive investment banker. On June 6, 2017, representatives from Bank B met with Mr. Brooks in Houston over dinner to further discuss the merits of a transaction between the two companies. On June 17, 2017, the Chairman of Bank B delivered a revised IOI proposing a cash purchase price of $70 million for CBI.

On June 21, 2017, Mr. Dueser called Mr. Brooks to indicate First Financial’s interest in pursuing a transaction with CBI. Mr. Dueser indicated that he would like to come to Kingwood and visit with Mr. Brooks. On June 22, 2017 Mr. Dueser met with Mr. Brooks in Kingwood. During afollow-up call between executives for

First Financial and Mr. Brooks, Mr. Dueser asked at what price for CBI would Mr. Brooks think CBI’s board of directors would consider a transaction with First Financial. Mr. Brooks told Mr. Dueser that it would require a price of $75 million.

On June 29, 2017, Mr. Brooks met with members of the executive committee to deliver the terms of the revised IOI. After deliberation, the executive committee determined that the offer was inadequate and a purchase price in themid-$70 million range would be needed in order for the executive committee to recommend a transaction to CBI’s board of directors. Mr. Brooks promptly delivered this information to Bank B. After further discussions, regarding a possible business combination. At each of these meetings, Mr. Baker,Bank B indicated that FBCit would be able to deliver an IOI with a purchase price of $74 million, but would require that CBI deliver tangible common equity at closing of approximately $48.5 million. Mr. Brooks indicated that once this revised offer was not readyprovided in writing, he would promptly review with the executive committee.

First Financial delivered anon-binding IOI dated July 3, 2017 to sell, butMr. Brooks proposing a purchase price of $75 million with a minimum equity requirement equal to CBI’s consolidated tangible common equity as of March 31, 2017. The IOI also indicated that FBC may be interestedthe purchase consideration would consist of $59.4 million in First Financial common stock and a transaction individend of $15.6 million from CBI’s retained earnings. Mr. Brooks visited with Hovde and a few members of CBI’s executive committee to discuss the future. Mr. Baker reported each of those conversationsIOI also on July 3, 2017. It was concluded that a few items within the IOI required further clarification before delivering the IOI to H. J. Shands, III, Chairman of the Board of FBC and First Bank, who in turn disclosed them to FBC’sCBI’s board of directors.

In September 2013,Over the next week, Mr. Baker introducedBrooks discussed key points in the IOI with executives from First Financial, as well as Hovde and members of CBI’s executive committee. It was determined that if CBI be allowed to dividend out any tangible common equity at closing in excess of its consolidated tangible common equity as of March 31, 2017 after paying or accruing transaction related expenses, CBI’s executive committee would recommend the IOI to the board of directors of CBI. On July 13, 2017, CBI’s board of directors convened to discuss the proposed terms of the IOI with Hovde. CBI’s board of directors concluded that if First Financial would fix the value of the stock portion of the purchase consideration at $59.4 million and the number of shares issued to CBI would vary, the board of directors would vote to authorize Mr. DueserBrooks to execute the IOI on behalf of CBI and continue negotiations and due diligence with First Financial. After adjourning the meeting, Mr. Brooks contacted First Financial to deliver this request. Later that afternoon, First Financial delivered a revised IOI with the requested terms to Mr. Shands by telephoneBrooks who then executed and returned the IOI to First Financial. Upon the execution of the IOI, due diligence commenced between the two companies.

On August 25, 2017 CBI received the initial draft of the reorganization Agreement from First Financial and the parties briefly discussed acontinued to negotiate the terms of the reorganization agreement until the document was executed on October 12, 2017.

During CBI’s board of directors meeting on September 20, 2017, legal counsel, Larry Temple, reviewed for CBI directors the fiduciary duties of directors under law, as well as the legal standards applicable to their decisions and actions with respect to the proposed business combination and the possibility of FBC and First Bank moving forward with a transaction. In March 2014, Messrs. Shands and Baker visited Mr. Dueser in Abilene, Texas. At this initial visit, the parties discussed the opportunities presented by a business combination between their institutions, the overall banking marketplace in southeast Texas and contiguous markets, the communities in which FBC and First Bank does business, the structure and nature of First Bank, and various potential transaction structures. Messrs. Dueser and Shands met in person again on May 9, 2014 in Colorado Springs, Colorado in furtherance of discussions regarding a proposed transaction.

Following the March and May 2014 meetings, the parties continued discussions regardingCBI’s legal counsel reviewed the terms and structureconditions of the Reorganization Agreement and ancillary legal documents with the board of directors, and discussed in detail the business points, contingencies and timing issues.

On September 26, 2017, the CBI board of directors met with its legal and financial advisors, to discuss the Reorganization Agreement which was in its substantially final form. During the meeting, the CBI directors heard a proposedpresentation from Hovde on the financial aspects of the transaction. As these discussions progressed, on September 24, 2014, First FinancialAt the conclusion of this discussion and FBC entered into a confidentiality agreementafter responding to facilitatequestions from the exchangedirectors, Hovde rendered to CBI’s board of information. In October 2014, Mr. Shands along with Messrs. Joe C. Denman, III and M. Richard Warner, each a director of FBC and First Bank, approached Vining Sparks regarding providing financial advicedirectors its oral opinion that the aggregate merger consideration to FBC in connection with a potential corporate transaction involving FBC.

The discussions between the parties and Vining Sparks then turned toward structuring a formal offerbe received from First Financial, to FBC regarding a proposed merger transaction, including a preliminary price range. On October 15, 2015, representativeswhich consisted of Vining Sparks provided FBC with its initial analysis regarding the

preliminary pricing range and structure offered by$59.4 million in shares of First Financial which analysis discussedcommon stock and a $15.6 million dividend from CBI to its shareholders in cash, subject to adjustment as provided in the attractivenessReorganization Agreement, was fair to the shareholders of the proposalCBI, from a financial point of view. Hovde’s oral opinion was subsequently confirmed by delivery of its written opinion, dated September 26, 2017, to CBI’s board of directors.

Based upon the board of directors’ review and discussion of the Reorganization Agreement, the opinion of Hovde and other relevant factors, CBI’s board unanimously authorized and approved the execution of the Reorganization Agreement with First Financial.

On October 22, 2014, First Financial submitted a formal offer to FBC in the form of a Letter of Intent. In the Letter of Intent, First Financial offered to purchase FBC for an aggregate purchase price of $59.0 million in the form of First Financial common stock, based on the market value ofSeptember 26, 2017, First Financial’s common stock at that time, and to pay FBC an additional $13.1 million to pay off its outstanding Subordinated Promissory Notes due June 30, 2028.

After input and recommendations of revisions to the Letter of Intent from the parties’ legal and financial advisors, FBC signed the revised Letter of Intent on October 22, 2014 and thereafter engaged Vining Sparks as its exclusive financial adviser in connection with the proposed transaction. This Letter of Intent had an expiration date of January 31, 2015 and a no-shop provision that prohibited FBC from pursuing and negotiating a transaction with another party during the term of the Letter of Intent.

Following the signing of the Letter of Intent, the executive management teams of First Financial and FBC met for dinner in The Woodlands, Texas on November 17, 2014 and discussed the proposed transaction.

During November and December 2014, the parties proceeded on an exclusive basis to perform regular and reverse due diligence investigations of each company and their respective subsidiaries. The two companies’ legal teams also began preparing and negotiating the terms of the reorganization agreement. During the due diligence period, First Financial conducted a thorough due diligence investigation of FBC. This due diligence investigation included on-site review of documents, files and other pertinent materials, including in-person meetings and discussions with key FBC personnel. FBC, together with its financial advisor, Vining Sparks and legal counsel, conducted a thorough reverse due diligence investigation of First Financial. This due diligence investigation included a review of current and historical public filings of First Financial and on-site review of material information and records of First Financial, as well as interviews with senior management.

In November 2014, the parties agreed that First Financial would directly repay FBC’s Subordinated Promissory Notes due June 30, 2028 rather than pay FBC cash for satisfying such debt obligations, as originally agreed.

From December 2014 through March 2015, management of First Financial and FBC negotiated the terms and conditions of the reorganization agreement, including, among other terms, the mix of consideration between stock and cash and price protection measures in the form of caps and collars applicable to the merger consideration. During this period, the term of the Letter of Intent was set to expire and First Financial and FBC agreed on January 14, 2015 to extend the deadline under the Letter of Intent until March 31, 2015 to allow the parties additional time to perform due diligence and negotiate the terms of the reorganization agreement.

The parties prepared several memoranda providing specific proposals of methodology for calculating the aggregate merger consideration and allocating risk related to any potential changes in First Financial’s market price, specifically in light of the recent volatility with the oil and gas industry and significant decreases in energy prices. After further negotiation, the parties agreed on a merger consideration calculation methodology based on a variable aggregate merger consideration with high and low collars of $61.0 million and $57.0 million, respectively, and a stock and cash mix based on any changes in First Financial’s average market value for a specified period prior to the closing date of the merger.

On March 16, 2015, FBC’s board of directors held a special meeting to review and discuss the proposed transactionmergers and the then current draft of the reorganization agreement.Reorganization Agreement. At thatthis meeting, the FBCFirst Financial’s board of directors was briefed on the terms of reorganization agreement and the related agreements and had the opportunity to ask questions to FBC’sreceived presentations from its legal and financial advisors regarding terms and conditions of the transaction as set forth in the reorganization agreement. Vining Sparks also presented an analysis of the financial terms set forth in the reorganization agreement. Vining Sparks provided FBC’scounsel, Norton Rose Fulbright US LLP. Following this discussion, First Financial’s board of directors with its opinion that consummation ofunanimously voted to approve the proposed transaction on those terms was fair toReorganization Agreement and the shareholders of FBC from a financial point of view.

Following this discussion, and after due consideration and deliberation, the board of directors of FBC unanimously approved theother transactions contemplated by the reorganization agreement,Reorganization Agreement, including the mergers, and authorized First Financial’s executives to execute the execution of the reorganization agreementReorganization Agreement.

On October 12, 2017, CBI and recommended the approval ofFirst Financial executed the reorganization agreement, and the transactions contemplated thereindirectors of CBI delivered to the shareholders of FBC.

On April 1, 2015, First Financial and FBC entered into the definitive version of the reorganization agreement, thetheir respective voting agreements and the director support agreements. FBC andLater that day, First Financial also issued a press release announcingannounced the transaction.transaction after the close of trading on the NASDAQ Global Select Market.

Recommendation of FBC’sCBI’s Board of Directors and its Reasons for the Merger

FBC’s board of directors believes that the merger is in the best interest of FBC and its shareholders. Accordingly, FBC’sCBI’s board of directors has unanimously approved the merger and the reorganization agreementReorganization Agreement and unanimously recommends that FBC’sthe CBI shareholders vote “FOR approval”merger proposal.

The terms of the reorganization agreement.

agreement, including the consideration to be paid to CBI shareholders, were the result of arms-length negotiations between the representatives of CBI and representatives of First Financial. CBI’s board of directors has determined that the merger is fair to, and in the best interests of, CBI’s shareholders. In approving the reorganization agreement, FBC’sReorganization Agreement, CBI’s board of directors consulted with Vining Sparks(a) the Hovde Group with respect to the financial aspects and fairness of the merger consideration, from a financial point of view, to the holders of shares of FBC common stockCBI shareholders and with(b) its outside legal counsel as toon its legal duties and the terms of the reorganization agreement. The board believes that combining with First Financial will create a stronger and more diversified organization that will provide significant benefits to FBC’s shareholders and customers alike.

The terms of the reorganization agreement, including the consideration to be paid to FBC’s shareholders, were the result of arm’s length negotiations between representatives of FBC and representatives of First Financial.Reorganization Agreement. In arriving at its determination, to approve the reorganization agreement, FBC’sCBI’s board of directors also considered a number of factors, including the following:including:

The reasons set out above for the merger are not intended to be exhaustive but do include theall material factors considered by theCBI’s board of directors of FBC in approving the mergerReorganization Agreement and the reorganization agreement.merger. In reaching its determination, the CBI board of directors of FBC did not assign any relative or specific weightweights to different factors, and individual directors may have given weightdifferent weights to different factors. Based on the reasons stated, above, the CBI board of directors of FBC believesbelieved that the merger iswas in the best interestinterests of FBC and itsCBI’s shareholders, and therefore the board of directors of FBCCBI unanimously approved the reorganization agreementReorganization Agreement and the merger. Each memberIn addition, all members of FBC’sthe CBI board of directors has agreedhave entered into voting agreements requiring them to vote the shares of CBI stock of FBCover which he or she hasthey have voting authority in favor of the reorganization agreement and the merger.Reorganization Agreement.

THE BOARD OF DIRECTORS OF FBCCBI UNANIMOUSLY RECOMMENDS THAT YOU VOTE (I) FOR“FOR” THE MERGER PROPOSAL TO APPROVE THE REORGANIZATION AGREEMENT AND (II) FOR“FOR” THE PROPOSAL TO ADJOURN THE SPECIAL MEETING, IF NECESSARY OR ADVISABLE, TO PERMIT FURTHER SOLICITATION OF PROXIES.ADJOURNMENT PROPOSAL.

Opinion of FBC’sCBI’s Financial Advisor

In October 2014, FBC engaged Vining Sparks IBG, LP. (“Vining Sparks”)The fairness opinion and a summary of the underlying financial analyses of CBI’s financial advisor, Hovde Group, LLC, is described below. The description contains projections, estimates and other forward-looking statements about the future earnings or other measures of the future performance of CBI. The projections were based on numerous variables and assumptions, which are inherently uncertain, including factors related to render financial advisorygeneral economic and investment banking services to FBC. Vining Sparks agreed to assist FBCcompetitive conditions. Accordingly, actual results could vary significantly from those set forth in assessingthe projections. You should not rely on any of these statements as having been made or adopted by CBI or First Financial. You should review the copy of the fairness from aopinion, which is attached as Appendix D.