There is some confusion as to whether he was one of the targets at Eastwood Hotel. or at Fitzwilliam Sq. He was not in his room.
I was contacted by the granddaughter of Cecil Stokes O’Callaghan , who believes that the target was him and it was in 3 Fitzwilliam Sq in Jan 1922. I do not think he is the man.
1890 Apr 1 Born (from 1939 Register, family think 1891) Son of Mark Stokes O'Callaghan
1901 census living at 340 Wellington Place, Pembroke West, Dublin
1911 census A visitor at Inch, Co Kerry. Born Co Cork
1912 Apr 10. 18th (County of London) Battalion, The London Regiment (London Irish Rifles); Cecil Mark Joseph O'Callaghan to be Second . Lieutenant. Only 8 months later on 18/12/1912 he resigns his commission.
1922 Jan 26. Married Marjorie Marie Thornton in Lewisham. His marriage certificate - where he is called Cecil Mark Joseph O'Callaghan, married on 26/01/1922 to Margery Manners in Eltham. His residence at the time of marriage is Eltham. The newspaper announcement of his marriage lists him as Mr C Stokes O'C of 3 Fitzwilliam Square, Dublin. She was the widow of Major R H Manners
1939 Census Cecil S O'Callaghan living at . He was Consulting Automobile Engineer. Wife Margery
1951 Died Bromley Kent. His will says Cecil Mark Joseph O'C otherwise known as Cecil Stokes O'C. He left £9300