1970-1974 - Secretary of State for education and science in the Conservative government of Edward Heath
1975 - Is elected leader of the Conservative Party.
1976 - In a speech, she lashes out against Communism. This causes the Soviet press to nickname her the "Iron Lady."
May 4, 1979 - Becomes prime minister after leading the Conservatives to electoral victory.
April 2, 1982 - Argentina invades the Falkland Islands. Thatcher immediately authorizes forces to recapture the Falklands. After a few months of fighting, Argentine troops surrender on June 14, 1982.
June 9, 1983 - Wins re-election in a landslide and gains a parliamentary majority with just over 42 percent of the vote.
1984 - Escapes an IRA terrorist bombing in Brighton at her hotel at the annual Conservative Party conference.
June 11, 1987 - The Conservative Party wins its third general election.
1989 - Thatcher introduces the poll tax, a charge levied on community residents rather than property. The unpopular tax leads to rioting in the streets and Thatcher's ouster by Conservative Party politicians worried that the tax and Thatcher's unpopularity would bring down the party.
November 1990 - Is forced to resign as prime minister after a leadership struggle within her own party.
March 7, 1991 - Receives the U.S. Medal of Freedom from President George Bush.
June 5, 1992 - Is named a life peer on the Queen's honor list. Thatcher's title is Baroness.
June 30, 1992 - Swearing-in ceremony at the House of Lords, where Thatcher formerly becomes the Baroness Thatcher of Kesteven.
July 1, 1993-June 30, 2000 - Is chancellor of the College of William and Mary, in Williamsburg, Va.
Feb. 4, 1994 - Formal investiture as chancellor of the College of William and Mary.
1995 - Autobiography, "The Path to Power" is published. Excerpts had appeared in the Daily Mirror and The Sunday Times of London in 1993.
March 22, 2002 - Retires from public life after suffering a series of small strokes.
June 11, 2004 - Attends Ronald Reagan's funeral services.
August 25, 2004 - South African police arrest Thatcher's son, Mark, on allegations he was involved in a plot to overthrow the government of Equatorial Guinea.
January 13, 2005 - Mark pleads guilty to unwittingly helping bankroll the coup plot. In exchange he receives a fine, a suspended jail sentence, and the right to join his family in the United States.