He was the eldest child of paper manufacturer Frank William Monckton (1861–1924), and his wife, Dora Constance (d.

Monckton served as advisor to King Edward VIII during the abdication crisis, having been Attorney General to the Duchy of Cornwall since 1932.

He worked in propaganda and information during the Second World War and became Solicitor General in Winston Churchill's 1945 caretaker government, although he refused to join the Conservative Party.

He finally joined the Conservative Party after the war and became a Member of Parliament for Bristol West at a 1951 by-election.

[2] He had wanted to become Lord Chief Justice of England and indeed had been promised the job by Churchill and the two subsequent prime ministers, but in 1957 he decided instead to join the board of Midland Bank.

It advocated a majority of African members in the Nyasaland and Northern Rhodesian legislatures and giving these territories the option to leave the Federation after five years.