Margaret Thatcher, 13 October 1925– 8 April 2013 was a Britishpoliticianwho served asPrime Minister of the UKfrom 1979 to 1990. The longest-serving prime minister of the 20th century she was the first woman to hold that office. A Soviet journalist dubbed her theIron Lady. As Prime Minister, she implemented policies that came to be known asThatcherism. Roifield proposes that her tenure kicks starts English and Scottish nationalism.