Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
BYRNE MARK JAMES
   2. Issuer Name and Ticker or Trading Symbol
Flagstone Reinsurance Holdings, S.A. [FSR] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
_____ Officer (give title below) __X__ Other (specify below)
Former Director and 10% Owner
(Last)
(First)
(Middle)
48 PAR LA VILLE ROAD, SUITE 504		 3. Date of Earliest Transaction (Month/Day/Year)
12/08/2010
(Street)

HAMILTON, D0 HM 11		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Shares 12/08/2010   S(1)   2,849,868 D $ 11.4823 0 I By Haverford (Bermuda) Ltd. (2)
Common Shares 12/08/2010   S(1)   5,155,156 D $ 11.4823 0 I By Limestone Business Limited (3)
Common Shares               50,000 I By Rebecca Byrne (4)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Warrant $ 14.8 12/08/2010   S(1)     7,955,553 12/01/2013 12/31/2013 Common Shares 7,955,553 $ 1.6969 0 I By Haverford (Bermuda) Ltd. (2)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
BYRNE MARK JAMES
48 PAR LA VILLE ROAD
SUITE 504
HAMILTON, D0 HM 11		       Former Director and 10% Owner

Signatures

 /s/Mark J. Byrne   12/10/2010
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) On December 8, 2010, Flagstone (Bermuda) Holdings, Limited entered into an agreement to purchase: (i) 8,005,024 shares of Flagstone Reinsurance Holdings, S.A. (the "Issuer") from Haverford (Bermuda) Ltd. ("Haverford") and Limestone Business Limited ("Limestone") and (ii) the Amended and Restated Share Purchase Warrant dated as of June 25, 2010 (the "Haverford Warrant"), issued to Haverford and exercisable for 7,955,553 shares, par value $0.01 per share, of the Issuer.
(2) The reporting person is the Chairman and Chief Executive Officer of Haverford, and therefore has investment and voting control over the 2,849,868 common shares of the Issuer held by Haverford and the Haverford Warrant.
(3) These common shares are held by Limestone, which is owned by a trust, established for the benefit of others, for which the reporting person is the settlor. The reporting person disclaims beneficial ownership of these shares.
(4) These common shares represent shares purchased in connection with the initial public offering of the Issuer and are owned by Rebecca Byrne, the wife of the reporting person. The reporting person disclaims beneficial ownership of these shares.

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