Media playback is unsupported on your device Media caption Nick Robinson looks back at the life of Margaret Thatcher

Margaret Thatcher, who has died following a stroke, was one of the most influential political figures of the 20th Century.

Her legacy had a profound effect upon the policies of her successors, both Conservative and Labour, while her radical and sometimes confrontational approach defined her 11-year period at No 10.

Her term in office saw thousands of ordinary voters gaining a stake in society, buying their council houses and eagerly snapping up shares in the newly privatised industries such as British Gas and BT.

But her rejection of consensus politics made her a divisive figure and opposition to her policies and her style of government led eventually to rebellion inside her party and unrest on the streets.

Father's influence

Margaret Hilda Thatcher was born on 13 October 1925 in Grantham, Lincolnshire, the daughter of Alfred Roberts, a grocer, and his wife, Beatrice.

KEY MOMENTS Born Margaret Roberts on 13 October 1925

First stood for Parliament in the 1950 election

Married businessman Denis Thatcher in 1951

Elected as Conservative MP for Finchley in 1959

Named education secretary by Ted Heath in 1970

Defeated Heath in Tory leadership contest in 1975

Became first female prime minister after Conservative election victory in 1979

Sends taskforce to regain control of the Falklands Islands in 1982

Wins landslide election victory in 1983

Fights year-long battle with mining unions in 1984-5

Survives IRA bombing of Brighton hotel during 1984 Conservative conference

Wins third general election victory in 1987

Resigns after facing leadership challenge in 1990

Stands down as MP in 1992 and awarded a peerage

Her father, a Methodist lay preacher and local councillor, had an immense influence on her life and the policies she would adopt.

"Well, of course, I just owe almost everything to my own father. I really do," she said later. "He brought me up to believe all the things that I do believe."

She studied chemistry at Somerville College, Oxford, and became only the third female president of the Oxford University Conservative Association.

After graduating she moved to Colchester where she worked for a plastics company and became involved with the local Conservative Party organisation.

In 1949, she was adopted as the prospective Conservative candidate for the seat of Dartford in Kent which she fought, unsuccessfully, in the 1950 and 1951 general elections.

However, she made a significant dent in the Labour majority and, as the then youngest ever Conservative candidate, attracted a lot of media attention.

In 1951 she married a divorced businessman, Denis Thatcher, and began studying for the Bar exams. She qualified as a barrister in 1953, the year in which her twins Mark and Carol were born.

She tried, unsuccessfully, to gain selection as a candidate in 1955, but finally entered Parliament for the safe Conservative seat of Finchley at the 1959 general election.

Within two years she had been appointed as a junior minister and, following the Conservative defeat in 1964, was promoted to the shadow cabinet.

'Milk snatcher'

When Sir Alec Douglas-Home stood down as Conservative leader, Mrs Thatcher voted for Ted Heath in the 1965 leadership election and was rewarded with a post as spokeswoman on housing and land.

She campaigned vigorously for the right of council tenants to buy their houses and was a constant critic of Labour's policy of high taxation.

Image caption She initially worked as a research chemist before training as a barrister

When Ted Heath entered Downing Street in 1970, she was promoted to the cabinet as education secretary with a brief to implement spending cuts in her department.

One of these resulted in the withdrawal of free school milk for children aged between seven and 11 which led to bitter attacks from Labour and a press campaign which dubbed her "Margaret Thatcher, milk snatcher".

She herself had argued in cabinet against the removal of free milk. She later wrote: "I learned a valuable lesson. I had incurred the maximum of political odium for the minimum of political benefit."

As one of the few high-flying women in politics there was, inevitably, talk of the possibility that she might, one day, become prime minister. Similar press speculation surrounded the Labour minister Shirley Williams.

Margaret Thatcher dismissed the idea. In a TV interview she said she did not believe that there would be a woman prime minister in her lifetime.

The Heath government was not to last. Battered by the 1973 oil crisis, forced to impose a three-day working week and facing a miners' strike, Edward Heath's administration finally collapsed in February 1974.

Housewife-politician

Thatcher became shadow environment secretary but, angered by what she saw as Heath's U-turns on Conservative economic policy, stood against him for the Tory leadership in 1975.

When she went into Heath's office to tell him her decision, he did not even bother to look up. "You'll lose," he said. "Good day to you."

Image caption She entered Downing St in 1979 with a mission to shrink the state and repair the country's finances

To everyone's surprise, she defeated Heath on the first ballot, forcing his resignation, and she saw off Willie Whitelaw on the second ballot to become the first woman to lead a major British political party.

She quickly began to make her mark. A 1976 speech criticising the repressive policies of the Soviet Union led to a Russian newspaper dubbing her "the Iron Lady," a title which gave her much personal pleasure.

Adopting the persona of a housewife-politician who knew what inflation meant to ordinary families, she challenged the power of the trades unions whose almost constant industrial action peaked in the so-called "winter of discontent" in 1979.

As the Callaghan government tottered, the Conservatives rolled out a poster campaign showing a queue of supposedly unemployed people under the slogan "Labour Isn't Working".

Jim Callaghan lost a vote of confidence on 28 March 1979. Mrs Thatcher's no-nonsense views struck a chord with many voters and the Conservatives won the ensuing general election.

Monetary policies

As prime minister, she was determined to repair the country's finances by reducing the role of the state and boosting the free market.

Cutting inflation was central to the government's purpose and it soon introduced a radical budget of tax and spending cuts.

You turn if you want to... the lady's not for turning To the 1980 Tory conference

Bills were introduced to curb union militancy, privatise state industries and allow council home tenants to buy their houses.

Millions of people who previously had little or no stake in the economy found themselves being able to own their houses and buy shares in the former state-owned businesses.

New monetary policies made the City of London one of the most vibrant and successful financial centres in the world.

Old-style manufacturing, which critics complained was creating an industrial wasteland, was run down in the quest for a competitive new Britain. Unemployment rose above three million.

There was considerable unrest among the so called "wets" on the Conservative back benches and that, coupled with riots in some inner city areas, saw pressure on Margaret Thatcher to modify her policies.

But the prime minister refused to crumble. She told the 1980 party conference: "To those waiting with bated breath for that favourite media catch phrase, the U-turn, I have only one thing to say. You turn if you want to... the lady's not for turning."

Falklands War

By late 1981 her approval rating had fallen to 25%, the lowest recorded for any prime minister until that time, but the economic corner had been turned.

In early 1982 the economy began to recover and, with it, the prime minister's standing among the electorate.

Her popularity received its biggest boost in April 1982 with her decisive response to the Argentine invasion of the Falkland Islands.

The prime minister immediately despatched a naval task force and the islands were retaken on 14 June when the Argentine forces surrendered.

Victory in the Falklands, together with disarray in the Labour Party, now led by Michael Foot, ensured a Conservative landslide in the 1983 election.

The following spring the National Union of Mineworkers called a nationwide strike, despite the failure of their firebrand president, Arthur Scargill, to ballot his members.

Margaret Thatcher was determined not to falter. Unlike the situation Edward Heath faced in 1973, the government had built up substantial stocks of coal at power stations in advance of the industrial action.

Third term

There were brutal clashes between pickets and police but the strike eventually collapsed the following March. Many mining communities never recovered from the dispute that hastened the decline of the coal industry.

In Northern Ireland, Mrs Thatcher faced down IRA hunger strikers, though her hard-line approach infuriated even moderate nationalist opinion and critics claimed it drove many young Catholics towards the path of violence.

Image caption She narrowly escaped death in an IRA attack on her Brighton hotel in 1984

Although she attempted to ease sectarian tensions, offering Dublin a role, peace efforts collapsed beneath the weight of Unionist opposition.

In October 1984, an IRA bomb exploded in the Conservative conference hotel in Brighton. Five people died and many others, including cabinet minister Norman Tebbit, were seriously injured.

Characteristically, the prime minister insisted on delivering a typically robust response in her keynote conference speech a few hours later.

"This attack has failed. All attempts to destroy democracy by terrorism will fail."

Her foreign policy was aimed at building up the profile of the UK abroad, something she believed had been allowed to decline under previous Labour administrations.

She found a soulmate in the US president, Ronald Reagan, who shared many of her economic views, and she struck up an unlikely alliance with Mikhail Gorbachev, the reforming Soviet president. "We can do business together," she famously said.

Labour, now led by Neil Kinnock, had still not recovered from years of in-fighting and Mrs Thatcher won an unprecedented third term at the 1987 general election.

One of her first actions was to introduce the poll tax or community charge, a flat-rate tax for local services which was based on individuals rather than the value of the property in which they lived.

'Treachery with a smile'

It sparked some of the worst street violence in living memory. Tory MPs, alarmed that the tax could cost them their seats, saw no way of getting rid of it so long as Margaret Thatcher was in charge.

She easily survived a leadership challenge from an unknown back-bencher in 1989 but the challenge was just a symptom of increasing dissatisfaction among Conservative MPs over her policies.

It was the issue of Europe which, eventually, brought about her downfall.

Returning from a fractious Euro summit in Rome, she let rip against her European counterparts, refusing to countenance any increase in the power of the European Community and outraging many colleagues.

Image caption She shed tears upon leaving office in 1990

"The President of the Commission, Monsieur Delors, said at a press conference the other day that he wanted the European Parliament to be the democratic body of the Community, he wanted the Commission to be the Executive and he wanted the Council of Ministers to be the Senate. No. No. No."

Sir Geoffrey Howe, resentful since being ousted as foreign secretary, seized his moment to quit the cabinet, deliver a devastating resignation speech and invite challengers for the leadership.

The following day, Michael Heseltine threw his hat into the ring. Falling two votes short of preventing the contest going to a second round, Margaret Thatcher declared she would fight on.

Told by close colleagues, the famous "men in grey suits," that she would lose, she used her next cabinet meeting to announce her resignation. Later, she mused bitterly: "It was treachery with a smile on its face."

John Major was elected her successor and Margaret Thatcher returned to the back benches, finally standing down as an MP in 1992 when the Conservatives, against all predictions, were again returned to power.

Later years

She was elevated to the peerage as Baroness Thatcher, of Kesteven in the County of Lincolnshire, receiving the Order of the Garter in 1995.

She wrote two volumes of her memoirs while remaining active in politics, campaigning against the Maastricht Treaty and condemning the Serbian policy of ethnic cleansing in Bosnia.

She publicly endorsed William Hague for the Conservative leadership in 1997 but pointedly failed to speak in favour of his successor, Iain Duncan Smith.

Image caption She continued to attend the House of Lords

She was forced to curtail her activities in 2001 when her health began to deteriorate. After a series of minor strokes, her doctors advised her against making public speaking appearances and she appeared increasingly frail.

She was also suffering from dementia which was affecting her short-term memory, something her daughter, Carol, would reveal in 2008.

When her husband Denis - whom she had described as her "rock" - died in 2003 aged 88, she paid him an emotional tribute.

"Being prime minister is a lonely job. In a sense, it ought to be - you cannot lead from a crowd. But with Denis there I was never alone. What a man. What a husband. What a friend."

A year later she travelled to the US to bid farewell to her political partner Ronald Reagan, whose funeral took place in Washington in June 2004.

She continued to appear in public, perhaps most notably when she unveiled a bronze statue of herself in the House of Commons, the first time a living former prime minister had been commemorated in this way.

And she returned to Downing Street. Gordon Brown invited her for tea, shortly after he became prime minister and she was back in 2010 as a guest of David Cameron, the new head of a coalition government.

Legacy

Few politicians have exercised such dominance during their term in office and few politicians have attracted such strength of feeling, both for and against.

To her detractors she was the politician who put the free market above all else and who was willing to allow others to pay the price for her policies in terms of rising unemployment and social unrest.

It is our duty to look after ourselves Margaret Thatcher, 1987 interview

Her supporters hail her for rolling back the frontiers of an overburdening state, reducing the influence of powerful trades union leaders and restoring Britain's standing in the world.

She was, above all, that rare thing, a conviction politician who was prepared to stand by those convictions for good or ill.

Her firm belief that deeply held convictions should never be compromised by consensus was her great strength and, at the same time, her greatest weakness.

For many, her philosophy was summed up in a magazine interview she gave in 1987.

"I think we have gone through a period when too many children and people have been given to understand 'I have a problem, it is the government's job to cope with it!' or 'I have a problem, I will go and get a grant to cope with it!'; 'I am homeless, the government must house me!' and so they are casting their problems on society and who is society?

"There is no such thing! There are individual men and women and there are families, and no government can do anything except through people and people look to themselves first.

"It is our duty to look after ourselves and then also to help look after our neighbour and life is a reciprocal business and people have got the entitlements too much in mind without the obligations."