 In 1919, he joined the Diplomatic Service and served at the British embassy in Belgrade from 1919 to 1922, at the Foreign Office from 1922 to 1930 and at the embassy in Moscow from 1930 to 1933.During his time in Moscow he played an important role in the Metro-Vickers engineers trial, in which six British engineers were accused of spying.He returned to the Foreign Office in 1933, and held office as head of the League of Nations section until 1937 and of the Central Department from 1937 to 1939.