Premiership of Margaret Thatcher Premiership of Margaret Thatcher Margaret Thatcher served as Prime Minister of the United Kingdom from May 1979 to November 1990. She became Prime Minister after serving as Leader of the Conservative Party since 1975. In domestic affairs, Thatcher is best known for her sweeping policies concerning the affairs of the economy, including the privatisation of most nationalised industries. In foreign policy, she fought a war against Argentina and played a key role with President Ronald Reagan and Soviet leader Mikhail Gorbachev in ending the Cold War. By the late 1980s, she was alienating many senior members of her Cabinet by
Deputy Prime Minister of the United Kingdom Tyne. William Whitelaw was Margaret Thatcher's "de facto" deputy from 1979–1988, an unofficial position he combined with that of Home Secretary in 1979–1983 and Leader of the House of Lords after 1983. Sir Geoffrey Howe was bestowed the title of Deputy Prime Minister by Thatcher in 1989, on being removed from the post of Foreign Secretary. He resigned as her deputy in 1990, making a resignation speech that is widely thought to have hastened Thatcher's downfall. Thatcher's successor John Major did not appoint a Deputy Prime Minister until 1995, when Michael Heseltine was given the post. John Prescott, who was