Raisley Stewart Moorsom was born on 8 February 1892 in the Lake District, into a family with a naval background. He was educated at Bedales School and came to King’s in 1911, where he became friends with Elliott Felkin and Goldsworthy Lowes Dickinson. He served during the First World War in the Westmorland and Cumberland Yeomanry.

After the war, Moorsom studied psychology at University College, London. He married Ann Thomson, a South African, in 1923, and they had three children. Moorsom had inherited money and had no need to work; he spent his days entertaining Bloomsbury friends and travelling. In the Second World War, Moorsom went to live with Elliott Felkin in New York; when he was unable to receive funds from England he worked as a taxi driver. On his return to England, he returned to his pre-war life, visiting Felkin in France and returning to the Lake District. He died on 9 June 1981.

For further biographical details of Raisley Stewart Moorsom, the reader is referred to the 'Annual Report of the Council, King's College, Cambridge', Oct. 1981, pp. 42-4.