A riddle, wrapped in a mystery, inside an enigma. Winston Churchill was talking about Stalin's foreign policy but much the same applies to the Russian orphan who grew up to be the world's fifteenth-richest man.

Chelsea fans invented the chant: “If you want the best then don't ask questions ‘cos Roman, he's our man. Where it all comes from is a mystery. Is it guns? Is it drugs? Is it oil from the sea?”

Roman Abramovich's spokesman is quoted in The Billionaire from Nowhere as saying: “There were a number of publications that tried to link Mr Abramovich with the Russian mafia, which anyone who knows the business world here understands is far-fetched.”

The tycoon was born on October 24, 1966, to a mother who died from an abortion before his first birthday. His father was crushed to death by a crane by the time he was 3.

He was sent to stay with his uncle in Ukhta, a town built and populated by political prisoners from Stalin's purges. Like many living there, the Abramovich family were Jews.

Mr Abramovich set himself up as a black-market street trader selling toys, before becoming the bagman to Boris Berezovsky, a Kremlin favourite and business aide to President Yeltsin. When Mr Berezovsky adopted too high a public profile, the Yeltsins are said to have turned to Mr Abramovich for discreet help.

Alexander Litvinenko, who was murdered in London, told The Times that Mr Abramovich became important enough to vet Vladimir Putin as President on behalf of the oligarchs.

Mr Abramovich's fortune comes from the privatised oil company Sibneft and interests in aluminium. He sold his aluminium shares to Oleg Deripaska for a reported $1.8 billion in 2003 and returned Sibneft to the Kremlin for £7.4 billion in 2005.

The young tycoon became governor of the Arctic region of Chukotka in 2001 and Mr Putin was reported to have insisted that he remain for a second five-year term. This week the new President Medvedev finally agreed to let Mr Abramovich resign.

Mr Abramovich and his second wife, Irina, 39, divorced last year. This spring he treated his new love, Daria Zhukova, 26, to paintings by Francis Bacon and Lucian Freud, which broke auction house records.

Mr Abramovich's lavish spending befits a man who can never be sure how long he has left. Many of his contemporaries died in the post-communist gang wars and he is protected by a squadron of bodyguards. But Russians say that he has never really changed, that he is happiest in the banya playing chess.

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