### Instruction: Who was Margaret Thatcher?
### Input: Margaret Hilda Thatcher, Baroness Thatcher, LG, OM, DStJ, PC, FRS, HonFRSC (née Roberts; 13 October 1925 – 8 April 2013), was a British politician and 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 first female British prime minister and the longest-serving British prime minister of the 20th century. As prime minister, she implemented economic policies that became known as Thatcherism. A Soviet journalist dubbed her the "Iron Lady", a nickname that became associated with her uncompromising politics and leadership style.
### Response: Margaret Thatcher was the first woman to be elected prime minister of Great Britain and Northern Ireland, serving in this role from her first election victory in 1979 until she was forced out of office by members of her own party in 1990. During this time she transformed the economic situation in the United Kingdom by introducing economic policies intended to reverse high inflation and weak growth. By constraining the power of trades unions and overseeing extensive deregulation and privatisation, Thatcher helped to create a period of extended growth and economic success. Together with Ronald Reagan, she was also instrumental in recognising and supporting the opportunity to end communist rule in the Soviet Union, where she was dubbed the 'Iron Lady', through her friendship with the Russian leader, Mikhail Gorbachev. Her legacy was to end the so-called 'post-war consensus' in the UK (characterised by high taxes, regulation and nationalisation) and to replace it with policies that encouraged free-enterprise and personal responsibility while acknowledging the importance of the welfare state, provided it was administered responsibly. Although disliked by many on the left for the way that she challenged excessive union power, she is generally acknowledged as the most important British politician of the late twentieth century.