Between 1947 and 1949 he served in the Black Watch and the 5th Battalion of the King's African Rifles before going up to Pembroke College, Cambridge, where he was known for his thespian talents, being president of the Footlights in 1951.

In 1966 he was appointed chairman of the Royal Eastern Counties Hospital for the mentally handicapped at Colchester, a job he considered the "most frustrating" of his life.

An agile mind and a winning manner enabled Andrew Davidson to carry out the demanding duties of Deputy Chief Whip in the House of Lords for six years, 1986–92, with skill and marked success.

As Deputy Chief Whip, he held the ancient but purely nominal office of Captain of the Yeomen of the Guard.

[3] He lost his seat in Parliament after the passing of the House of Lords Act 1999, commenting: "I am getting on and maybe the younger generation should get a shot at it.