The United Kingdom fought a short, sharp war against Argentina over the Falklands Islands under Thatcher in 1982, responding with force when Buenos Aires laid claim to the islands.
Announcing that Britain had recaptured South Georgia Island from Argentina, Thatcher appealed to nationalist sentiments, advising the press: "Just rejoice at the news and congratulate our forces."
A journalist shouted a question at her as she turned to go back into 10 Downing Street: "Are we going to war with Argentina, Mrs. Thatcher?"
She paused for an instant, then offered a single word: "Rejoice."
Controversy over Falklands war
The conflict was not without controversy, even in Britain.
A British submarine sank Argentina's only cruiser, the General Belgrano, in an encounter that left 358 Argentines dead. The sinking took place outside of Britain's declared exclusion zone.
In her first term, Thatcher reduced or eliminated many government subsidies to business, a move that led to a sharp rise in unemployment. By 1986, unemployment had reached 3 million.
But Thatcher won landslide re-election in 1983 on the heels of the Falklands victory, her Conservative Party taking a majority of seats in parliament with 42% of the vote. Second-place Labour took nearly 28%, while the alliance that became the Liberal Democrats took just over 25%.
A year later, she escaped an IRA terrorist bombing at her hotel at the Conservative Party conference in Brighton.
She was re-elected in 1987 with a slightly reduced majority.
She was ultimately brought down, not by British voters, but by her own Conservative party.
Brought down by the poll tax
She was forced to resign in 1990 during an internal leadership struggle after she introduced a poll tax levied on community residents rather than property.
The unpopular tax led to rioting in the streets.
She married her husband, Denis Thatcher, a local businessman who ran his family's firm before becoming an executive in the oil industry, in 1951 -- a year after an unsuccessful run for Parliament. The couple had twins, Mark and Carol, in 1953.
She was elected to Parliament in 1959 and served in various positions, including education secretary, until her terms as prime minister.
Thatcher was awarded the U.S. Medal of Freedom by President George H. W. Bush in 1991, a year after she stepped down as prime minister. She was named Baroness Thatcher of Kesteven after leaving office.
She retired from public life after a stroke in 2002 and suffered several smaller strokes after that. Her husband died in June 2003.
Though her doctors advised against public speaking, a frail Thatcher attended Reagan's 2004 funeral, saying in a prerecorded video that Reagan was "a great president, a great American, and a great man."
"And I have lost a dear friend," she said.
In the years that followed she encountered additional turmoil. In 2004, her son Mark was arrested in an investigation of an alleged plot by mercenaries to overthrow the president of Equatorial Guinea in west Africa. He pleaded guilty in a South African court in 2005 to unwittingly bankrolling the plot.