MBRG Middleburg Financial Corp.

CUSIP No. 596094102

Explanatory Note

This Amendment No. 3 to Schedule 13D is being filed by the undersigned to amend the Schedule 13D filed by the reporting person on March 31, 2016 (as amended by Amendment No. 1 on April 20, 2016 and further amended by Amendment No. 2 on April 29, 2016, collectively, the “Schedule 13D”). This Amendment No. 3 amends the Schedule 13D as specifically set forth.

No material change.

No material change.

No material change.

Item 4 of the Schedule 13D is hereby amended to add the following:

“On October 21, 2016, Access National Corporation (“Access”) and Issuer entered into an Agreement and Plan of Reorganization (the “Merger Agreement”) pursuant to which Issuer will merge with and into Access (the “Merger”). Access will be the surviving corporation in the Merger. The Merger Agreement was unanimously approved by the Boards of Directors of both companies.

As a result of the Merger, the holders of shares of Issuer common stock will receive 1.3314 shares of Access common stock for each share of Issuer common stock held immediately prior to the effective date of the Merger. The shareholders of Access will own approximately 53.5% of the combined entity and the shareholders of Issuer will own approximately 46.5%.

Mr. Sokol voiced his support for the Merger in a press release dated October 24, 2016 (the “Press Release”) issued jointly by Access and Issuer.”

The foregoing descriptions of the Merger Agreement and the Press Release do not purport to be complete and are qualified in their entirety by reference to the full text of the Merger Agreement, which is filed as Exhibit 2.1 to the Current Report filed by Access on Form 8-K on October 25, 2016, and the Press Release, which is filed as Exhibit 99.1 to the Issuer’s Current Report filed on Form 8-K on October 24, 2016, and are incorporated herein by reference.

Reference is hereby made to Item 6 for a description of the Voting and Standstill Agreement executed concurrently with the Merger Agreement, which provides for various rights and obligations of the parties thereto.

No material change, except that the 2,103,008 shares of common stock beneficially owned by Mr. Sokol now represent 29.61% of the Issuer’s issued and outstanding common stock, calculated based on 7,101,864 shares of common stock, par value $2.50 per share, as reported in the Issuer’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2016 filed with the Securities and Exchange Commission on August 9, 2016.

Voting and Standstill Agreement

Simultaneous with the execution of the Merger Agreement, Access and Issuer entered into a Voting and Standstill Agreement (the “Voting and Standstill Agreement”) with David L. Sokol and the David L. Sokol Revocable Trust (the “Trust”). Pursuant to the Voting and Standstill Agreement, Mr. Sokol and the Trust agreed to vote all shares of Issuer common stock beneficially owned by Mr. Sokol and the Trust in favor of the Merger and the Merger Agreement, and against any competing acquisition proposal or any action, proposal, transaction or agreement that could be expected to impede, interfere with, delay, discourage, adversely affect or inhibit the timely consummation of the Merger or the fulfillment of Issuer’s or Access’s conditions under the Merger Agreement.

Also pursuant to the Voting and Standstill Agreement, Mr. Sokol and the Trust agreed until the earlier of the effective date of the Merger or the termination of the Merger Agreement, except as consented to in writing by Access and Issuer or as expressly contemplated by the terms of the Voting and Standstill Agreement or the Merger Agreement, to not (i) sell, transfer, tender, pledge, encumber, assign or otherwise dispose of any shares of Issuer common stock subject to the Voting and Standstill Agreement, subject to certain limited exceptions, (ii) acquire, offer to acquire or agree to acquire any assets of Issuer or any subsidiary or division thereof, (iii) make or participate in any solicitation of proxies to vote, or seek to influence any person with respect to voting, shares of Issuer common stock other than to publicly disclose Mr. Sokol’s support of the Merger and the Merger Agreement, (iv) submit to Issuer any shareholder proposal under Rule 14a-8 of the Securities Exchange Act of 1934 (the “Exchange Act”), (v) make any public announcement with respect to, or submit a proposal for or an offer of any extraordinary transaction involving Issuer or Access, or securities or assets of either, other than the Merger and the transactions contemplated by the Merger Agreement, and (vi) form, join or participate in a “group” (as defined in Section 13(d)(3) under the Exchange Act) in connection with any of clauses (i) through (v) above. Mr. Sokol agreed to cease any existing activities, discussions or negotiations conducted prior to the date of the Voting and Standstill Agreement with respect to any competing acquisition proposal, and agreed to not and to not authorize any of his representatives to (a) solicit, initiate, or knowingly encourage, facilitate or induce any inquiries relating to or the submission of a competing acquisition proposal, (b) participate in any discussions or negotiations regarding, or furnish any non-public information or data with respect to, any competing acquisition proposal, or (c) enter into any agreement, arrangement or understanding with respect to any competing acquisition proposal or that requires Mr. Sokol to abandon, terminate or fail to perform actions required by the Voting and Standstill Agreement.

The foregoing description of the Voting and Standstill Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Voting and Standstill Agreement, which is attached hereto as Exhibit 99.3, and is incorporated herein by reference.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Exhibit Index