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
Premiership of Margaret Thatcher 1989, Lawson and Foreign Secretary Geoffrey Howe forced Thatcher to agree to the circumstances under which she would join the Exchange Rate Mechanism. At the meeting, they both threatened they would resign if their demands were not met. Thatcher responded by moving Howe to Leader of the House of Commons (despite giving him the title Deputy Prime Minister he was now effectively removed from decision-making over Europe) and by listening more to her adviser Sir Alan Walters on economic matters. Lawson resigned that October, feeling that Thatcher had undermined him. Thatcher continued to be the leading international advocate of a