Lynda,
Sydney Claude Hamilton BEGBIE was born in 1897, in London, the
son of Sydney Dawson Begbie & Maude Mary Begbie; the family
residence in 1901 was Acton, Middlesex, but by the time of the
war the family was living at 3 York Terrace, Regent's Park, London.
Begbie served with the 3rd Battalion of the East Surrey Regiment
and transferred later to the Royal Flying Corps. He flew single seat
scout aircraft with 74 Squadron, in France, and his death date is
22 April 1918 (as you stated). I do not have any additional information
about his wartime service, the circumstances of his death, or a
photograph--perhaps some of these can be found in the excellent
history of 74 Squadron, TIGER SQUADRON, by J.I.T. (Ira) Jones,
who was also one of the squadron's most renowned aces.
regards, josquin