His Officer file has him as both "Frederick" and "Reginald Frederick" I think he was born Reginald Slee, and later joined up underage using Frederick Hart
1892 Feb 6. I cannot get his birth. Certainly not born as "Hart" in Barnstaple. It is probably Reginald George F Slee in Holdsworthy , Devon
1901 census at Fleet St Swansea "Reginald Slee"
1911 census the family is at 7 Prospect Terrace West Cross, Swansea, as on his service record for his mother.
1907 Aug 1. Enlisted. Claiming to be born 6 Feb 1888. His wife put his age then as being born 1892
1911 census . Command Communication Company, Polygon Camp, Abbassia, Cairo, Egypt, Private 1st Bn Welch Regiment . Gives born Barnstaple
1914 Aug 27 Landed in France
1916 Apr 9. Commissioned - Welsh Reg. Co. Serjt.-Maj. Frederick Hart.
1916 May 31 A Miss Gertrude Cooke wants to know about him
1917 Feb 1. Married Elizabeth Jane Gould Pedler
1917 Dec 29 MC gazetted. 2nd Lt. (A /Capt.) Frederick Hart, Welsh R
1918 May 18. Welch Regt. The undermentioned Lts. relinquish the actg. rank of Capt.: — F. Hart, M.C., on ceasing to be empld. as Adjt.
1919 May 28. Welch Reg.—Lt. F. Hart, M.C., relinquishes the actg. rank of Maj.
1919 Jul 19. Greek Military Cross gazetted. Lieutenant (acting Major) Frederick Hart, M.C., Welsh Regiment.
1920 Apr 7. Welch R. — Lt. F. Hart, M.C., retires, receiving a gratuity, and is granted the rank of Maj .
1921 Jun 23 Joined ADRIC with service no 2079. Posted to Depot Coy
1922 Jan 23. Discharged on demobilisation of ADRIC
1935 Apr 5. Died in Barnsley - All in same officer file in TNA covers both "Frederick" and "Reginald Frederick"