Born Margaret Hilda Roberts in 1925, Margaret Thatcher grew up in Grantham. Her father was a grocer, and involved in politics and Methodist religion. She studied chemistry at Oxford, receiving BA and MA degrees, and leading the Oxford University Conservative Association in 1946.

While working as a chemist, she ran unsuccessfully for parliamentary election, and married affluent businessman Denis Thatcher in 1951. She then studied law, gave birth to twins, and in 1958 was elected as Conservative MP for Finchley. From 1970 to 1974 she was Education Secretary in Ted Heath's Conservative government. After Heath lost the 1974 national election, Thatcher challenged him for the leadership of the party and won.

The 1978-79 "Winter of Discontent" of unrest by organised labour unions led to the election of 1979, with Margaret Thatcher defeating Jim Callaghan's Labour Party. Margaret Thatcher hoped to reverse imperial decline and reduce what she saw as the negative effects of the state on business and enterprise. She began privatising state-owned industries and public housing built after the war, and cutting spending. The 1981 recession cut her popularity, but after the 1983 Falklands war she recovered to win the 1984 election.

A proposed reform of local government taxation called the "Poll Tax", because of its link to voter registration, led to unpopularity, a riot in 1990, and resignation in late 1990.