1782 vote of no confidence in the government of Lord North

This a list of the successful votes of no confidence in British governments led by Prime Ministers of the Kingdom of Great Britain and subsequently the United Kingdom. The first such motion of no confidence to befall a ministry was in 1742 against Sir Robert Walpole, a Whig who served from 1721 to 1742 and was the de facto first Prime Minister to hold office. Thereafter there have been 21 votes of confidence successfully motioned against British governments. The most recent vote was against the ministry of James Callaghan, a Labour Party prime minister who had succeeded Harold Wilson as a result of a 1976 leadership election. Following defeat, Callaghan was forced to hold a general election by May 1979; he was defeated by Margaret Thatcher of the Conservative Party.

Before the vote in 1979, the most recent vote of no confidence in a British government was in 1924, the longest interval in British parliamentary history.

The 1742 vote of no confidence in the government of Sir Robert Walpole was the first time that a Prime Minister of Great Britain resigned after a vote of no confidence by the House of Commons. Walpole is regarded as the first British prime minister, although he did not officially enjoy that title. He had been continually in office since April 1721 and relied the continuance of his government on the confidence of the King as well as that of Parliament.

...
Wikipedia