By Nyta Mann BBC News Online political correspondent

Iain Duncan Smith's election as Conservative leader is a remarkable turn in the political career of a man previously best known for destabilising his own government.

Iain Duncan Smith

Born 9 April 1954 Joined Tory Party in 1981 Married Hon Elizabeth Wynne Fremantle 1982; four children Unsuccessfully fought Bradford West 1987 Elected MP for Chingford 1992 Shadow social security secretary 1997-99 Shadow defence secretary 1999-2001 Wins Tory leadership September 2001

Tory members have chosen for their top job a figure who was frequently at the heart of the parliamentary Euro-troubles that contributed significantly to the chaos which engulfed John Major's premiership.

It was Duncan Smith who, for example, helped orchestrate rebellion after rebellion against the Maastricht Bill in 1992 and 1993. It will be interesting to see how he deals with Tory MPs defying the party whip now that he is the one who wields it.

Stiff upper lip background

The new Tory leader's stiff-upper-lip, military background stood him in good stead with Conservative grassroots. His father, W G G "Smithy" Duncan Smith, was a pilot in the Battle of Britain, a friend of Douglas Bader with 19 "kills" to his name.

Baroness Thatcher: Iain Duncan Smith has long been a disciple

Iain, the youngest of four children, was educated at HMS Conway, a school for sons of military personnel. After that came a spell in Italy as a language student, then Sandhurst.

In 1975 he was commissioned into the Scots Guards, which saw him serving in Northern Ireland and as aide de camp to Major-General Sir John Acland, commander of the Commonwealth monitoring force in Zimbabwe.

Heir to Tebbit

It was no surprise when Baroness Thatcher backed Duncan Smith as her choice for leader; he has long been a standard bearer of the Thatcherite right. While he was still in the army, her triumph at the 1979 election was a major influence on him.

He joined the Tory Party in 1981 - the same year he left the forces to make his way on Civvy Street.

His first stop was the defence contractor GEC Marconi as a sales and marketing executive, a job that kept him in close touch with the military. In 1988 he moved to the property company Bellwinch, only to be made redundant the following year.

Ken Clarke was in government while the new leader was voting against it on Europe

His next job put him back in contact once more with his old colleagues as marketing and development director of the publications Jane's Defence Weekly and Jane's Fighting Ships.

In the meantime, he attended to his political career. In 1987 he contested the safe Labour seat of Bradford West.

It took another five years for him to reach the Commons. When Norman (now Lord) Tebbit announced his intention to stand down, Duncan Smith's deep Euroscepticism, support for traditional family values and keen Thatcherism made him the natural heir for his Chingford seat.

It was Tebbit who at the start of the leadership contest praised Duncan Smith, father of four, as "a remarkably normal family man with children" - a barb aimed directly at then-frontrunner Michael Portillo.

'Hawk, hanger and flogger'

Portillo and Duncan Smith fell out in 1995 when the former failed to challenge John Major for the leadership. A disappointed Duncan Smith backed John Redwood instead.

He again backed Redwood in 1997, proposing him in the contest eventually won by William Hague.

Michael Portillo's failure to challenge John Major disappointed to his Eurosceptic allies

He is a firm believer in the free market and a member of the Thatcherite No Turning Back Group - deserted by Portillo last year.

A hawk on defence matters, he is fiercely opposed to the European rapid reaction force and strongly in favour of US plans for the "son of star wars" National Missile Defence system which is causing disquiet among European and other governments.

Need to broaden appeal

During the contest he attracted criticism that his views hark back to the past and appeal only to the narrow and dwindling band of core Tory supporters, at a time when the party desperately needs to broaden its appeal to today's voters.

He is firmly on the socially authoritarian wing of the party: against abortion and gays in the military, in favour of capital punishment and the return of caning in schools - positions that led to Ken Clarke to describe him as a classic Tory "hanger and flogger".

In the final weeks of the campaign he sought to play down his Tory hard right credentials.

He insisted he did not identify himself as a right-winger, declaring that the concepts "left" and "right" meant little to him.

He also suggested he would look again at his previous support for Section 28, which bans local authorities from "promoting" homosexuality.

Low profile an advantage

The Conservative Party's new leader comes to the job with an exceedingly low profile. This feature was a worry for him during the campaign to win the ballot of Tory members but is a potential advantage now that he is safely home.

Being as yet unknown to the wider public allows the new leader more freedom to rebrand and reposition a party the electorate still seems in no mood to allow back into government.

Whether he takes up the opportunity to do so could be one of the key factors in the task of rescuing his party from the crisis that currently surrounds it.