Douglas-Hamilton was one of four brothers who made history by simultaneously being at the rank of squadron leader or above at the outset of World War II, he himself commanding No. 603 Squadron RAF from 18 December 1941 till 20 July 1942.
Educated at Harrow, and Balliol College, Oxford. Douglas-Hamilton saw active service between 1939 and 1944, flying Spitfires in Operation Torch over Malta. On return to Britain, he was killed whilst carrying out reconnaissance over the French coast, and crashed in southern England.
At the 1934 Empire Games he won the bronze medal in the heavyweight class of the boxing tournament.