He was the creator of the Department of External Affairs, and collaborated with Michael Joseph Savage and Peter Fraser.

[1] He was then transferred to Washington, D.C., where he served as Minister to the United States between 1944 and 1952 (and, in this role, signed the ANZUS Treaty on behalf of New Zealand).

In late 1967 he was appointed as member of the team headed by UN envoy Gunnar Jarring to establish peace in the Middle East following the Six-Day War.

He was born in Sydney, Australia, and educated (LLM) at Victoria University College.

[5] Berendsen married Nellie Ellis Brown at St John's Church, Wellington on 15 December 1917.