George Osborne, 38, today became the youngest Chancellor of the Exchequer to take charge at the Treasury for over a century.
But while few doubt his talent, questions have been raised over whether he has the experience and judgment to manage the nation's finances at such a critical time.
Like his friend David Cameron, he comes from a background of wealth and privilege as heir to a baronetcy with a fortune reportedly in excess of £4 million.
But he is also something of a political high-wire act who has more than once found himself in hot water.
In 2005 - when he was managing Mr Cameron's successful leadership campaign - he was hit by the appearance in a Sunday newspaper of a photograph of him taken in his 20s with a woman described as a "cocaine-snorting hooker".
More seriously, his career almost came off the rails three years later when he was hit by allegations that he tried to solicit a donation from a Russian oligarch in breach of party funding legislation.
Although Mr Osborne denied the claim - and the Electoral Commission eventually ruled there was no evidence of an offence - the so-called "yachtgate" affair threw an unwelcome spotlight on the lifestyle of the Tory elite.
It arose out of a holiday he spent at the Corfu villa of his old university friend Nat Rothschild, a hedge fund manager and member of the banking dynasty, where he was introduced to the Russian aluminium magnate Oleg Deripaska.
Mr Rothschild subsequently alleged that Mr Osborne had found the opportunity so good, he invited Tory fundraiser Andrew Feldman, who was staying nearby, to join him on Mr Deripaska's yacht, Queen K, "to solicit a donation" for the party.
Mr Rothschild hit out after apparently having been angered by Mr Osborne's treatment of another of his circle of guests that summer - Lord Mandelson, who was yet to rejoin the Government.
When, a few weeks later, he was made Business Secretary by Gordon Brown, Mr Osborne was quickly identified as the source of a newspaper story claiming Lord Mandelson had "dripped pure poison" about the Prime Minister during his stay on the island.
Although no donation was made and the allegations were fiercely denied by the Tories, some senior Conservatives feared Mr Osborne had been so badly damaged he would be unable to carry on, although in the event Mr Cameron determined to stand by his friend.
Born on May 23 1971, the son of a baronet and beneficiary of a family trust linked to the Osborne and Little wallpaper firm, his early career in many ways echoed that of Mr Cameron, five years his senior.
At Oxford, where he studied modern history, he was a member of the upper class Bullingdon Club, a dining society notorious for its drunken behaviour.
Like Mr Cameron, on leaving university he did a stint working at the Conservative Research Department, before entering Parliament in the 2001 general election, taking the seat of Tatton in Cheshire.
Both men were part of the so-called "Notting Hill set" of bright young modernisers who gathered around Michael Howard after he became Tory leader in 2003.
When Mr Howard decided to stand down following the Conservatives' election defeat of 2005, he appointed Mr Osborne shadow chancellor providing him with a platform from which to launch a leadership bid.
In the event however, he agreed to back Mr Cameron - apparently without the acrimony which had marked a similar deal between Mr Brown and Tony Blair a decade earlier.
In 2007 he was credited with helping to derail Mr Brown's plans for a snap general election with his promise to abolish inheritance tax on estates worth up to £1 million if the Tories won.
And his announcement that a Conservative administration would reverse Labour's planned 1p rise in National Insurance contributions dominated the early weeks of the General Election campaign.
Mr Osborne has shown himself a deft political operator on the road to power. He now faces the far greater challenge of showing he can be equally adept in dealing with Britain's worst-ever deficit as Chancellor.