In 1975, Thatcher defeated Heath in the Conservative Party leadership election to become Leader of the Opposition. This victory made Thatcher the first woman to lead a major political party in the United Kingdom.

Thatcher would go on to become Prime Minister of the country in 1979, and would not leave office until 1990.

Thatcher passed away on April 8, 2013 at the age of 87.

She wrote two volumes of memoirs, The Downing Street Years (1993) and The Path to Power (1995).

Thatcher was known as the “Iron Lady.”