The son of Henry and Florence Grenfell, Eustace Osborne Grenfell served in the Territorial Force for a little over a year before being promoted to Lieutenant in the Royal Garrison Artillery. He received Royal Aero Club Aviator's Certificate 966 on a Maurice Farman biplane at Central Flying School, Upavon on 9 November 1914. Posted to France with 1 Squadron on 3 June 1915, he was promoted to Captain and scored his first victory in September 1915. By 17 January 1916, Captain Grenfell had bagged six enemy aircraft flying the Morane Parasol N. He then returned to England to serve as an instructor at the Royal Central Flying School. In the fall of 1916 he was back in France, with 60 Squadron, and he scored two more victories flying Nieuport scouts before he crashed and broke his leg on 11 December 1916. Post-war, Squadron Leader Grenfell received the Distinguished Flying Cross, gazetted on 30 May 1924, "in recognition of distinguished services rendered with the Waziristan Force between January, 1922 and April, 1923." Wing Commander Grenfell was promoted to Group Captain "with effect from 1 January 1937" and retired from the Royal Air Force on 17 February 1942.
Great Britain, Royal Aero Club Aviators' Certificates, 1910-1950
British Army WWI Medal Rolls Index Cards, 1914-1920
Military Cross (MC)
Lieutenant (temporary Captain) Eustace Osborne Grenfell, Royal Artillery and Royal Flying Corps.
For conspicuous gallantry and skill. He attacked single-handed and brought down three Fokker aeroplanes.
Captain Grenfell has shown great bravery and initiative at all times.