The chief of the British Secret Intelligence Service from 1939 to 1952, Menzies was an Eton-educated Guards officer who had fought in France at Ypres and earned the Distinguished Service Order and the Military Cross before being posted to Sir John Haig’s headquarters staff at Montreuil. After the war, he joined SIS and headed the military section until his chief, Adm. Sir Hugh Sinclair, fell ill with cancer in 1938 and was incapacitated.