Sir William McMahon was the 20th prime minister of Australia, serving from 1971 to 1972. He held office as the leader of the Liberal Party of Australia, and previously held various ministerial positions from 1951 to 1971, the longest continuous service in Australian history. Born: February 23, 1908 Died: March 31, 1988 In office: March 10, 1971 – December 5, 1972 Wiki link