Margaret Thatcher Margaret Thatcher Margaret Hilda Thatcher, Baroness Thatcher, (; 13 October 19258 April 2013) was a British stateswoman who served as Prime Minister of the United Kingdom from 1979 to 1990 and Leader of the Conservative Party from 1975 to 1990. She was the longest-serving British prime minister of the 20th century and the first woman to hold that office. A Soviet journalist dubbed her "The 'Iron Lady, a nickname that became associated with her uncompromising politics and leadership style. As Prime Minister, she implemented policies known as Thatcherism. A research chemist at Somerville College, Oxford, before becoming a barrister, Thatcher
Prime minister could command the loyalty of the Commons was increasingly necessary. The long tenure of the wartime prime minister William Pitt the Younger (1783–1801), combined with the mental illness of George III, consolidated the power of the post. The title was first referred to on government documents during the administration of Benjamin Disraeli but did not appear in the formal British Order of precedence until 1905. The prestige of British institutions in the 19th century and the growth of the British Empire saw the British model of cabinet government, headed by a prime minister, widely copied, both in other European countries