Boris Berezovsky's self-imposed exile in London and the south of France since 2000 was his way of escaping Russian court prosecutors. In his last interview he said he longed to return to his own country. He had lost his standing amidst Kremlin inner circles when he became a fierce critic of Vladimir Putin. Eventually, his fortunes plummeted and he sank into debt. A former mathematician, when the old Soviet "empire" crumbled he had managed to profit from sweeping privatisations. Among his powerful friends was Boris Yeltsin. British expert James Nixey, at The Royal Institute of International Affairs, described him: "Boris Berezovsky in some ways is the archetypal and original Russian oligarch. He was initially one of the richest. He made his money through cars and through metals and through oil. He was able to force his way through the pack and to become one of the most influential businessmen, and business and politics are very intertwined in Russia. They are now; they were in the 1990s - and he had influence with then President Yeltsin. Berezovsky and fellow oligarchs raised some serious cash for Yeltsin's campaign in the 1996 elections, and he won. It wasn't just the money; it was also through this business elite's control of television networks. Berezovsky was soon named to high official positions, at one stage even deputy secretary of Russia's security council, or playing a government role in removing Russian forces from Chechnya, negotiating a peace treaty and helping to coordinate the economic reconstruction of the war-torn country. At the end of the 1990s, Yeltsin's reign was drawing to a close, and Berezovsky's circle favoured a relative unknown to succeed him: Vladimir Putin. It was to be the death knell for Berezovsky's ambitions. James Nixey said: "Of course, Putin was not Yeltsin, who was a much weaker man, and so when Putin came in he felt the oligarchs had too much power, and Berezovsky as the leading oligarch in many ways was sidelined, he was made an example." Granted political asylum in Britain, Berezovsky dreamt of overthrowing Putin. Meanwhile, the Russian authorities tried him in absentia on charges of criminal fraud and found him guilty, but he was not extradited. Other countries - such as Brazil and France - acted against him, his property or transactions - with or without Moscow asking them to. Last year in London, his loss in a huge case claiming civil damages from another Russian businessman, Roman Abramovich, took another crushing toll. More about: Death, Inquiry, Justice, Russia, United Kingdom