ROMAN Abramovich, one of the world's wealthiest men, and Boris Berezovsky, once seen as the Soviet Union's most powerful oligarch, are locked in an epic legal wrangle.
Abramovich forced Berezovsky to sell him billions of pounds of shares cheaply by threatening that Vladimir Putin would seize his assets if he did not comply, a court has heard.
It is claimed Abramovich, the billionaire owner of Chelsea Football Club, conned his former friend and mentor out of more than £2bn (¤2.3bn).
The case saw two of Britain's richest men go head to head as they made allegations about Kremlin intrigue and protection rackets in a High Court case worth £3.5bn (¤4bn).
It is thought special security measures have included sweeping the court for bombs and ensuring the building is sniper-proof.
In one of the only times the pair have come face to face in more than 10 years after they fell out following a meeting, the pair sat at opposite ends of a court room in London, dressed in expensive suits and surrounded by their entourage and dozens of highly paid lawyers.
Berezovsky claims that he was threatened at a meeting in his mansion in Cap d'Antibe in the south of France and forced to sell his shares in Sibneft, a Russian oil and gas conglomerate the two men had created with a third partner.
Abramovich is said to have vowed to get Putin, then the president and now the prime minister of Russia, to reclaim Berezovsky's assets and to prevent the release of one of his friends from jail.
It was claimed the Chelsea owner was "a man to whom wealth and influence mattered more than friendship and loyalty", said Laurence Rabinowitz representing Berezovsky.
However, Abramovich claims that the two were never friends and that he only hired Berezovsky to provide political influence and protection from Chechen gangsters.
Without acknowledging each other, the pair listened to the opening of the High Court case, one of the most expensive in legal history, which is expected to last three months and see both of them give evidence.
Mr Rabinowitz told the hearing: "This is a case about two men who worked together to acquire an asset that would make them wealthy beyond the wildest dreams of most people and who in the process, we say, became and remained good friends."
He said they fell out when Berezovsky, who had adopted a high political profile in Russia through his control of media outlets including a television station called ORT, fell foul of the Kremlin and was forced to leave the country and seek asylum in Britain.
That, he said, left Abramovich in a position where he was "in effect required to make a choice -- to remain loyal to Berezovsky, his friend and mentor and the person to whom he owed his newly acquired great fortune, or instead, as we submit, to betray Berezovsky and to seek to profit from his difficulties".
"It is our case that Abramovich at that point demonstrated that he was a man to whom wealth and influence mattered more than friendship and loyalty and this has led him, finally, to go so far as to even deny that he and Berezovsky were actually ever friends," Mr Rabinowitz told the court.
Abramovich claims he was being generous in taking the loss-making ORT off Berezovsky's hands and agreeing to a substantial pay-out of £800m (¤935m).
The case continues.