Gavyn Davies gave evidence to the Hutton Inquiry
BBC chairman Gavyn Davies has resigned from his post as head of the corporation's board of governors following the publication of the Hutton report.
Mr Davies' appointment in 2001 was met with accusations of cronyism.
But since the David Kelly affair he has led the corporation's defence of its handling of the situation and its journalistic standards.
From the outset he spoke on behalf of the governors to back the integrity of the BBC - and to spell out what he believed was the impartiality and accuracy of its reporting on the Iraq dossier affair.
And he clashed repeatedly with 10 Downing Street's director of communications, Alastair Campbell, over the BBC's reporting of the Iraq war, giving evidence to the Hutton Inquiry.
When his appointment to chairman was announced, the move was met with both approval and derision because of his long-term support for Labour.
But recent developments have seen relations strained as Mr Davies defended the corporation, accusing the Number 10 press office of attacking the "whole integrity of the BBC".
And he repudiated accusations BBC governors' acted too softly in their approach to the controversial report by journalist Andrew Gilligan and blindly supported managers in the face of outside criticism.
This criticism once again brought out arguments for self-regulation to be taken away and handed to Ofcom, the communications regulator.
One of the chief complaints surrounding his appointment to chairman was because of his friendship with chancellor Gordon Brown, despite it being made by an independent panel.
Mr Davies' wife Sue Nye is political secretary to Mr Brown and when the chancellor attempted to soften his image by posing with his then-fiancée Sarah Macaulay at a children's birthday party, it was in Mr Davies' London house with his son, Ben.
But Mr Davies was also well regarded by John Major's Conservative government and the self-made tycoon was already BBC vice-chairman so knew the corporation inside out.
He was one of Kenneth Clarke's economic wise men, and his brother-in-law Rick Nye was a speech writer for William Hague.
Born in Zimbabwe to Welsh parents, Mr Davies started his career in the civil service following an Oxford education.
He is a close friend of Chancellor Gordon Brown
For five years he worked in the Downing Street policy unit, as an adviser to both Wilson and Callaghan.
When Margaret Thatcher came to power he moved to the City, eventually being headhunted by US investment giant Goldman Sachs.
His shrewd dealings are believed to have netted him an estimated £150m personal fortune.
One share deal alone was reported to have brought him £15m.
At one time he was linked with the deputy governorship of the Bank of England, but was said to have turned it down because no guarantee was offered that he would succeed governor Eddie George.
Mr Davies' first taste of the BBC was as a guest economist on news programmes.
Later he was drafted in to chair a committee into the future funding of the BBC.
Many of the ideas put forward were controversial, including a proposal to add a levy on TV licences to fund digital services.
This idea was swiftly dismissed by the Culture, Media and Sport Select Committee.
Mr Davies is a keen supporter of Southampton Football Club, even going so far as trying to buy the club with Sir David Frost in 1996.
Mr Davies and his wife live in Wandsworth with their children Rosie and Ben and have a second home in Devon.