Profile: Mikhail Khodorkovsky
Mikhail Khodorkovsky was first arrested in October 2003 on charges of tax evasion, fraud and embezzlement.
The former head of oil giant Yukos and at the time Russia's richest man, he was jailed in 2005 for eight years and had been due for release in 2011.
However in 2009 he was put on trial again (along with his jailed partner Platon Lebedev) on further charges of embezzlement and money laundering.
He was again convicted, and jailed for 14 years - to run concurrently with the earlier sentence. So he faces imprisonment until 2017. His lawyers intend to appeal.
Khodorkovsky, 47, made his fortune - estimated at more than $15bn (£9.72bn) according to Forbes magazine - from the controversial post-Soviet privatisation of state assets.
Before his arrest, he was not just rich but very influential.Political activities
His lawyers have always maintained that the charges against him are trumped up, carried out on the orders of senior figures in the Kremlin who objected when his activities strayed into the political arena.
Mikhail Khodorkovsky Timeline
- 1963 - Born in Moscow, son of chemical engineers
- 1981 - Enters Medeleyev Chemistry Institute, Moscow
- 1980s - Sets up computer software business with fellow students
- 1987 - Founds Menatep bank
- 1994 - Buys Apatit fertiliser company at auction
- 1995 - Buys Yukos for $350m, with Menatep assuming $2bn in debt
- 2003 - Arrested for tax evasion, embezzlement and fraud
- 2004 - First court case begins
- 2005 - Found guilty on six of seven charges, jailed for eight years
- 2007 - Yukos declared bankrupt
- March 2009 - Second court case starts in Moscow
- December 2010 - Convicted of embezzlement and money laundering
Khodorkovsky had provided funding to nearly all political parties, including the communists, and acquired the rights to publish the prestigious Moskovskiye Novosti newspaper. He also hired a well-known investigative journalist critical of then-President Vladimir Putin.
While still in charge of Yukos, he consistently said he was not tied to any particular party. "Large companies cannot finance political parties as their shareholders and employees have different political views."
However he had made no secret of his support for the liberal opposition to Mr Putin.
When asked about Khodorkovsky on live television before the second trial verdict was read out, the former president - who is now prime minister - compared him to convicted US fraudster Bernard Madoff, saying simply: "a thief must be in jail."
The former tycoon's initial jail sentence kept him behind bars during the 2007 presidential elections and his wife, Inna, said recently she was sure he would remain in jail for the campaign in 2012.Knockdown price
A native of Moscow and the son of two engineers, Khodorkovsky studied at Mendeleyev Chemistry Institute and began his career as a loyal Soviet-era Communist Party member, running a computer import business under the wing of the party's youth movement (Komsomol) in the 1980s.
In 1987 - four years before the fall of the USSR - he founded what would become Menatep, one of post-Soviet Russia's first private banks.
He made his first millions in the 1990s when the bank acquired massive amounts of shares in companies that were privatised for bargain prices.
Fertiliser firm Apatit was bought in 1994 by Khodorkovsky and Lebedev for $283m, later becoming the focus of the initial trial against them.
His business empire, prosecutors later claimed, was little short of a gangster operation and Apatit shares were alleged to have been picked up illegally via the use of umbrella companies.
In 1995, Khodorkovsky acquired Yukos at a state auction at the knockdown price of $350m.
It had come close to folding but now Yukos became Russia's second biggest oil company, pumping one in every five barrels the country produced.
It began publishing its accounts to international standards and was soon seen as one of Russia's most transparent, well-run companies with international investors clamouring to own shares.
The man behind its modernisation, Mikhail Khodorkovsky, even served as deputy fuel and oil minister during Boris Yeltsin's presidency.
But after Vladimir Putin came to power, the Yukos chief executive's increasingly political activities aroused suspicions of his own ambitions.Bankruptcy
In July 2003, fellow Yukos shareholder Platon Lebedev was arrested for fraud in a step widely seen as a warning to Khodorkovsky to keep out of politics. Four months later, armed security forces detained him on his private jet at an airport in Siberia.
End Quote Mikhail Khodorkovsky November 2010
It's not me and Platon Lebedev who are now standing trial, it's all the Russian people”
Tax police filed enormous claims for unpaid taxes against Yukos and, unable to pay, the company filed for bankruptcy in 2006. Its production assets were sold off at state-run auctions.
As Yukos disappeared as a legal entity in November 2007, Khodorkovsky and his fellow inmate Platon Lebedev served much of their sentences at a Soviet-era labour camp in the Chita region of eastern Siberia, 4,700km (3,000 miles) east of Moscow.
They were moved to Moscow in early 2009 to face their second trial which involved charges of misappropriating nearly 1 trillion roubles ($27.7bn) and laundering almost 450bn roubles ($12.5bn).
As the trial itself drew to an end, Khodorkovsky himself predicted that his release was unlikely but warned that the fate of all Russians rested on the case.
"It's not me and Platon Lebedev who are now standing trial, it's all the Russian people," he told the court in his final address.
He went on to say that he had no wish to die in jail but "if that is what is needed, I have no hesitation".Man of 'ideals'
Khodorkovsky's son, Pavel, told the BBC that his father had never even considered pleading guilty to the charges although he was a realist and was ready to spend more time in prison.
"He talked about it and said it outright that 'I am not an ideal man but I have ideals'."
And in the days before the judge announced his verdict, Khodorkovsky made it clear that he saw the prime minister as the cause of his plight.
"I wish for Putin that people did not fear him but loved him," he wrote in an article for Nezavisinaya Gazeta.
He added that he felt pity for someone who seemed "so lonely in front of this limitless and merciless country" and who wore an "armour of ice" that could be penetrated only by "a love for dogs".
The reference was apparently to recent images of the prime minister caressing a Bulgarian shepherd dog but his coruscating remarks only added to the expectation that Mikhail Khodorkovsky's term in jail was far from over.