Third Thatcher ministry to make way for a leader more likely to win the next general election. Her successor was the Chancellor of the Exchequer John Major, who was elected on 27 November 1990, and who at 47 became the youngest Conservative Prime Minister of the 20th century. <section begin="June 1987 to July 1989" /> <section begin="July 1989 to November 1990" /> Members of the Cabinet are in bold face. Third Thatcher ministry Margaret Thatcher was Prime Minister of the United Kingdom from 4 May 1979 to 28 November 1990, during which time she led a Conservative government. She was the first woman
Thatcher effect Thatcher effect The Thatcher effect or Thatcher illusion is a phenomenon where it becomes more difficult to detect local feature changes in an upside-down face, despite identical changes being obvious in an upright face. It is named after the late British prime minister Margaret Thatcher, on whose photograph the effect was first demonstrated. The effect was originally created in 1980 by Peter Thompson, Professor of Psychology at the University of York. The effect is illustrated by two originally identical photos, which are inverted. The second picture is obviously altered so that the eyes and mouth are vertically flipped, though the