Alexander Frederick Douglas-Home served as Prime Minister for a year from October 1963 to October 1964. He became famous for a series of records. He was the last member of the House of Lords to be appointed Prime Minister, the only Prime Minister to resign from the Lords and contest a by-election to enter the House of Commons and the last Prime Minister actively chosen by a British monarch.

Douglas-Home was born in London, the eldest son of a Scottish earl. From 1918 he held the courtesy title Lord Dunglass. His brother was the dramatist, William Douglas-Home. After an education at Eton College and Christ Church, Oxford, he became a Conservative MP in 1931.

His aristocratic roots gave him a head start in the party as it then was, and he was soon appointed secretary to Neville Chamberlain, witnessing at first hand the latter's attempts to stave off World War II though negotiation with Adolf Hitler.

He lost his parliamentary seat in the 1945 general election, but regained it in 1950. However he was being forced to resign it in 1951, when he inherited his father's seat in the House of Lords, becoming 14th Earl of Home. Lord Home was appointed Foreign Secretary in 1960. In 1962, he was created a knight of the Order of the Thistle, which, in the event, entitled him to be styled "Sir" after renouncing his earldom.

In 1963 the Conservative prime minister, Harold Macmillan, suddenly resigned as an indirect result of the Profumo scandal. Under the then rules the leadership of the Conservative Party was not decided by a vote party members but by a decision of the party's elder statesmen. Though Rab Butler, nominally the "Deputy Prime Minister" was the favourite among Conservative MPs the elder statesmen preferred Home, some of them indicating that they would refuse to serve in cabinet under Butler and the other potential candidate, Quentin Hogg.

Outgoing Prime Minister Harold Macmillan advised Queen Elizabeth II of the opinion of the senior figures in the party. The Queen duly invited the Earl of Home to become Prime Minister and First Lord of the Treasury. Home believed it impractical to serve as Prime Minister. Using the Peerage Act 1963 passed earlier in the same year to facilitate the resignation from the Lords of Viscount Stangate (Tony Benn) Home resigned his peerage and as Sir Alec Douglas-Home contested a by-election in a safe seat engineered by the deliberate resignation of a Conservative MP. Home duly won, entering the history books as the last peer to become Prime Minister and the only Prime Minister to resign the Lords to enter the Commons.

The government had been too badly damaged to survive, however, and the Labour Party under the new leadership of Harold Wilson won the general election of October 1964. Home remained leader of the party until his resignation in July of the following year.

In 1974, Home was restored to the House of Lords when he accepted a life peerage, and became known as Baron Home of the Hirsel (The Hirsel being his family seat in Berwickshire) for the rest of his life. Home was the second-longest lived British Prime Minister behind Harold Macmillan. On his death, his son, David, succeeded him as Earl of Home.