Noble and statesman. Educated at Ampleforth College and Christ Church, Oxford, Kerr joined the Scots Guards and served in Britain during World War II. When only 18, he succeeded his cousin, Philip Kerr, the 11th Marquess of Lothian, who died suddenly in Washington in 1940. Kerr fought to try to recover some of the property which had been given away by his cousin.
In 1943, Kerr married Antonella (Tony) Newland, who went on to found the Women of the Year Lunch in 1955.
After the war, Kerr became an active member of the House of Lords, where he took the Conservative whip. In 1954, he was appointed a member of the controversial Wolfenden Committee on Homosexual Offences and Prostitution. Kerr supported the British legation at the United Nations during the Suez Crisis of 1956 and was later a representative at the Council of Europe and the Western European Union. He joined the Government in 1960, as Parliamentary Private Secretary to Alex Douglas-Home (1903-95), then Foreign Secretary. He went on to serve in the Ministry of Health and was appointed Under-Secretary of State in the Foreign Office in the Health administration of 1970, with responsibility for African affairs and disarmament. He ended his career in public service as Lord Warden of the Duchy of Cornwall.
One of Britain's leading land-owners, with estates at Monteviot in the Scottish Borders, Melbourne Hall in Derbyshire and Newbattle Abbey in Midlothian, Kerr was one of the first to realise the public interest in visiting grand houses and opened Melbourne Hall to the public in 1952.
A devout Roman Catholic, Kerr was appointed a Knight of Malta. He was also a member of the Royal Company of Archers, the Queen's ceremonial bodyguard in Scotland.
He died at his home, Ferniehirst Castle. He fathered six children, two sons and four daughters, and was succeeded by his eldest son Michael Ancram (b.1945).
