Margaret Hilda Thatcher, Baroness Thatcher  was the first female Prime Minister of the United Kingdom. She was prime minister from 1979 to 1990. She led the Conservative Party from 1975 to 1990. She was often known by the nickname, "The Iron Lady", given to her by a Soviet journalist.

Thatcher directed British troops in 1982 to get back the Falkland Islands from Argentina. Argentina had taken the Falklands for a short time during the Falklands War. She had the second longest single prime ministerial term in history. She married Denis Thatcher; they had twins: son Mark and daughter Carol.

She suffered from strong opposition during a miner's strike in 1984 and 1985, which took away political power from the coal miners' union. There was also controversy when she introduced a poll tax to Britain. This caused rioting across the country.

After being forced to resign by her own party, she was replaced by John Major in 1990. In 1992, she stood down as an MP and became Baroness Thatcher of Kesteven, joining the House of Lords.

During Thatcher's years as prime minister, unemployment rose by a lot, doubling during her first term, reaching 3 million in 1982. It started to decline again only in the late 1980s, and since the mid-1990s, Britain has consistently had lower unemployment than most of continental Europe. Thatcher's supporters claim this is the result of her structural reform of the labour market, though this is disputed by opponents.

She died from a stroke on 8 April 2013 in London, England. In line with her wishes she received a ceremonial funeral, including full military honours, with a church service at St Paul's Cathedral on 17 April. Queen Elizabeth II and Prince Phillip attended the funeral, the second time in the Queen's reign that she had attended the funeral of a former prime minister.