Russian oligarch Boris Berezovsky has lost his High Court battle with Chelsea Football Club owner Roman Abramovich.
Mr Berezovsky, 66, was seeking more than £3 billion damages after accusing the 45-year-old Russian billionaire businessman of blackmail, breach of trust and breach of contract.
Mr Abramovich denied the allegations and denied that Mr Berezovsky was entitled to damages.
Mrs Justice Gloster ruled in Mr Abramovich's favour after a trial in London which started in October 2011 and ended in January this year.
The legal fight centred on deals done in Russia following the break-up of the Soviet Union two decades ago.
Mr Berezovsky - who attended court for the ruling - told the trial Mr Abramovich had "intimidated" him into selling shares in a Russian oil company at a fraction of their value. He also told the judge Mr Abramovich had broken a promise made during a deal relating to a Russian aluminium company.
Mr Abramovich disputed the claims, saying they were "wholly without merit".
Both men "rose to enormous wealth and influence" in Russia in the 1990s as state-owned firms were privatised in the wake of the collapse of communism, the court heard.
But Mr Berezovsky fled Russia, never to return, in late 2000, after falling out with president Vladimir Putin. He travelled initially to France, then settled in England. He claimed that he had been betrayed by his former friend and business partner.
Announcing her decision, Mrs Justice Gloster said she found Mr Abramovich "to be a truthful, and on the whole reliable, witness". She said she dismissed Mr Berezovsky's claims both in relation to Sibneft and in relation to RusAl "in their entirety".