He served during the First World War in Somaliland, and was Winston Churchill's Chief of Staff from 1940, but retired from the British Army in 1946. He then served as chief of staff to Lord Mountbatten, then Viceroy of India. In 1951 he was made Secretary of State for Commonwealth Relations, and in 1952 became the first Secretary General of NATO, a post he held until 1957.

{| border="2" align="center" |- |width="30%" align="center"|Preceded by:
New Creation |width="40%" align="center"|Baron Ismay |width="30%" align="center"|Followed by:
Extinct |}