Bob Diamond was the standout face of fat cat bankers' pay who last year told MPs that the time for apologies was over. Since then he has apologised again – several times.
Diamond, 60, only became chief executive of Barclays at the beginning of 2011. But there was never any doubt that he was the only man to take over from John Varley, who was related by marriage to one of the Quaker families which founded the bank more than three centuries ago.
Diamond joined Barclays in 1996 at a time when some executives were questioning whether it had made the right move creating a huge investment bank following the Big Bang deregulation which happened a decade earlier.
A staunch Republican, he not only convinced them it was right but that it should be pursued even more aggressively. By 2004 he was the head of Barclays Capital – a name which the bank is now desperately trying to shed under its "One Barclays" campaign.
BarCap surged under the leadership of Diamond and his two lieutenants Jerry del Missier and Rich Ricci. In the best years it accounted for two-thirds of Barclays' entire profits.
Diamond also almost single-handedly struck the deal to buy the New York arm of Lehmans, after it went bust in September 2008, for a knock-down price of £1.1bn. He was only thwarted from buying the UK operations by the then Chancellor Alistair Darling.
At that time, one senior insider said, the upper floors of Barclays Canary Wharf headquarters was split between: "'Bob's people' and 'John's people' – you couldn't be both. I think John was a little scared of Bob and I suspect Marcus Agius [who resigned as chairman on Sunday] is too."
Diamond was also a key figure in negotiating the injection of fresh capital into Barclays by Middle-East sovereign wealth funds during the global financial crisis rather than looking to the UK taxpayer for a bailout.
But his massive pay packages – £17.7m last year – and tax arrangements have always drawn the ire of politicians. His personal wealth is reckoned to be north of £100m. Lord Mandelson branded him as the "unacceptable face of banking" when it was claimed he picked up £63m in a single year when Barclays sold its fund management arm in which he held shares.
Robert Edward Diamond Jr, a father of three, was brought up in Massachusetts as the eldest of nine children, and spent the first year of his working life as a lecturer teaching a business course to students at the University of Connecticut. But he soon switched from teaching to banking and spent 15 years at Wall Street's Morgan Stanley before switching to Credit Suisse ahead of joining Barclays.
He and his wife Jennifer live in Kensington but also have US homes in Manhattan, overlooking Central Park, and on the island of Nantucket in New England.
He is an avid fan of Chelsea Football Club and the Boston Red Sox baseball team. A season ticket holder at Stamford Bridge, he also presented the Barclays-sponsored Premier League trophy to club captain John Terry three times over the last seven years.
Diamond enjoys a good lifestyle but eschews the "Porsche and Petrus" ostentation of more junior investment bankers. He even claims to be a fan of the soap EastEnders.
He is a philanthropist who has a picture of himself shaking hands with the Pope. He is a trustee and generous backer of the Mayor's Fund for London. Boris Johnson once said: "Bob Diamond is the Mayor's best friend." That certainly was helped with the bank's sponsorship of London's Boris Bikes hire scheme.
It is just over a year ago that Diamond told MPs at the Treasury Select Committee: "There was a period of remorse and apology for banks. I think that period is over."
Today, when he appears again that same committee is unlikely to hear another apology from him.
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