In November 1990, the UK's prime minister made her tearful departure from 10 Downing Street. She was ousted by her own party, having been weakened by an unlikely enemy.

As Margaret Thatcher stood on the doorstep of the British prime minister's official residence for a final time, she faced the full glare of the world's media. "We're leaving Downing Street for the last time after 11.5 wonderful years, and we're happy to leave the UK in a very much better state than when we came here," she said. Thatcher looked anything but happy. Less than a week earlier, on 22 November 1990, she had resigned as head of the ruling Conservative Party after failing to win enough support in a leadership contest to carry on with authority. Close to tears, she waved goodbye, then headed for the familiar journey to Buckingham Palace for one last audience with Queen Elizabeth II. Ironically, it was her own increasingly regal management of her party that led it to turn against her.

As Britain's first ever female prime minister, Thatcher had led her party to victory in three general elections. Few politicians have wielded such power during their time in office or inspired such strong feelings, both for and against. She fought and won countless battles against the British establishment, the trade unions, the opposition Labour Party, and most fiercely, her own cabinet. But now she had lost the ultimate fight with her party colleagues, and, in defeat, she felt deeply betrayed. It is a story of hubris, hurt feelings and some very British sporting metaphors.

One of her ministers, Chris Patten, told the BBC in 2005 that Thatcher recognised "people need to be a bit scared of you if you're going to get your own way". Patten said that she had an "extraordinary style of summarising the conclusions of meetings at the beginning and then challenging the assembled company to say whether they thought she might be wrong". He added: "There was always that slight sense of the anaconda in the chandelier if you got things wrong."

Thatcher said in 2005 that as a trained scientist, her approach was to first gather the information rigorously then deliver her verdict. "I think sometimes the prime minister should be intimidating. There's not much point being a weak, floppy thing in the chair, is there?"

When Thatcher won a rare third term at the 1987 general election, one of her first actions was to announce the introduction of the controversial community charge, or "poll tax", a local council levy which required every resident to play a flat rate regardless of income. In March 1990, the levy sparked riots in London's Trafalgar Square, and Tory MPs were worried that the tax could cost them their seats. The prime minister's leadership was called into question for the first time. However, it was the issue of the UK's relationship with Europe that would bring about her eventual downfall.

No one would have predicted that Sir Geoffrey Howe would play such a crucial role in dethroning the Iron Lady. The MP was known for being mild-mannered: in 1978, a Labour MP likened a rhetorical offensive by Sir Geoffrey to "being savaged by a dead sheep". He admitted to Newsnight in 2005: "My manner of argument is one of tenacious repetition. I don't like shouting at people, whereas I was shouted at to some extent. I think that can be quite irritating if you're a quiet, consistent badger. That doesn't always please the person who prefers badger........

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