Chelsea owner Roman Abramovich funded "palaces in France", "private aircraft", "jewellery for his girlfriend" and "valuable paintings" for his billionaire business partner- who later tried to sue him for £3bn.
Boris Berezovsky and Abramovich traded accusations and gave onlookers a glimpse into the lifestyles of the super-rich during the three-month trial thought to have cost tens of millions of pounds in legal fees.
They were both escorted by bodyguards and sat in either corner of the courtroom during attended hearings - never speaking to each other.
Roman Abramovich bought Chelsea football club in 2003
Berezovsky went into business in the 1980s, started a political career in the 1990s, then went into "self-imposed exile" in 2000 following a fall-out with president Vladimir Putin.
Abramovich's lawyers said Berezovsky was a "power broker" and a "highly controversial figure" in Russian politics in the 1990s.
They said Berezovsky agreed to provide "protection or (in Russian) krysha" and Abramovich's companies paid Berezovsky "two billion dollars" between 1995 and 2002 for services as a "political godfather".
They said a woman had once delivered "five million in dollar bills" to Berezovsky - an allegation Berezovsky denied.
Abramovich's lawyers said Berezovsky had a "lively sense of his own importance" and some of his actions appeared to conform to the "classic psychology of the political exile".
The judge was told that the two men first met on a Caribbean cruise in 1994, when Abramovich was 28.
Abramovich was trading in oil and had the idea of creating a "vertically-integrated" oil company.
His lawyers said Berezovsky saw the plan as "offering the opportunity for great wealth".
The world's longest motor yacht 'Eclipse', owned by Abramovich, moored on the seafront off the coast of Antibes, southern France
Abramovich said he had "never aspired to be a public figure".
In a witness statement, he outlined his business career and referred to his "acquisition" of Chelsea, in 2003, in a section headed "political and charitable" activities.
Abramovich told the court that his purchase of Chelsea "impacted" his way of life "significantly" and was a "turning point".
The judge was told of some of the properties Abramovich had owned including Fyning Hill, a 420-acre estate and house in West Sussex; Lowndes Square, a large London property near Knightsbridge; and a "multimillion-pound" French chateau "which once belonged to the Duke and Duchess of Windsor".
She heard detail from a travel itinerary showing that Abramovich had once flown from Moscow to London and back in a day for a meeting.
Abramovich, right and his girlfriend Daria Zhukova, watches as Kiev's Dynamo
And Abramovich told how he once bought a businessman an aeroplane to say thanks for help with a deal.
Abramovich said he "felt a strong emotional bond" to Berezovsky but "hesitated to call him a former 'friend'".
"There was at times something of a megalomaniac about him that could lead to fantastic suggestions on his part," he said.
"As an example, one of his ideas was to restore monarchy in Russia.
"The grander the plan he entertained at any given time, the more cash he would be after in his almost-fanatical zeal to seek to make those grand plans a reality."
Abramovich said when Berezovsky left Russia in 2000 his accounts had been frozen and "all he had was one million dollars".
Russian oligarch Boris Berezovsky, (centre right), arrives at the High Court
Abramovich added: "He would not have lived long on that one million dollars."
One of Abramovich's business associates told the judge that Berezovsky once "threatened" a former employee in a text signed "Dr Evil".
A lawyer representing Berezovsky said the allegation was untrue.
Berezovsky said Abramovich was "ruthless" but "good at appearing to be humble", "good at getting people to like him" and "good at psychology".
Berezovsky told the judge of his "anger and frustration" at Abramovich's "disgraceful behaviour", and said: "Abramovich betrayed (me) despite the generosity (I) showed him."
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