Boris Berezovsky, who has died aged 67, was the most prominent and colourful of the so-called oligarchs, the group of powerful Russian businessmen who grew rich from the wholesale privatisation of state assets that followed the collapse of Soviet Communism.

Berezovsky’s transformation in little more than a decade from a Soviet mathematics professor and systems analyst earning 500 roubles (£12.18) a month to a multibillionaire was one of the most extraordinary and revealing stories of the immediate post-Communist era.

Berezovsky rose to prominence in the early 1990s by diligently cultivating Boris Yeltsin and his influential daughter Tatyana Dyachenko. As the Russian president and his advisers struggled to get a grip on Russia’s bankrupt economy, he showed great financial skills as well as the ability to charm and manipulate politicians. He became the king of Kremlin intrigue, regarded by his many enemies as a latter- day Rasputin.

Berezovsky emerged as one of a group of seven businessmen who oversaw and influenced the break-up of Russia’s state sector, securing the lion’s share of the spoils for themselves. His particular prizes were the airline Aeroflot, the Siberian oil company Sibneft, and a 49 per cent stake in the state television station ORT, which he used to ensure Yeltsin’s re-election as president in 1996. By the end of the process, Berezovsky and his oligarch colleagues owned well over half of Russia’s entire GDP.

Berezovsky’s success had little to do with the market economics in which he professed to believe. He simply used his powers of persuasion, his political contacts and his ability to grant personal favours to turn the cash flow of former state enterprises his way. “Privatisation in Russia goes through three stages”, he explained in 1995. “First, the privatisation of profit; second, privatisation of property; third, the privatisation of debt. Aeroflot is now going through the intermediate stage between privatisation of profit and property. We want to take part in both.”

Physically, Berezovsky bore a strong resemblance to his fellow billionaire, the Italian media mogul and prime minister Silvio Berlusconi, and he shared Berlusconi’s taste for the good life, his undeniable charm, his shady business reputation — and his interest in political power.

But while Berlusconi tapped into something deep in the Italian psyche, Berezovsky was regarded with hatred and suspicion by ordinary Russians who blamed him for their country’s parlous economic condition. In 1994 Berezovsky’s chauffeur had his head blown off by a bomb intended for his employer, who walked away from the explosion unscathed.

Berezovsky went on to support Vladimir Putin in his bid to become Russian president in 2000, funding the pro-Kremlin, pro-Putin Unity party and churning out pro-Putin propaganda on ORT. But his arrogance proved his undoing. In response to public anger and to secure his own position, Putin turned on his former backer. In 2001 Berezovsky fled to France, and later to Britain pursued by allegations of fraud and corruption.

Boris Berezovsky was born in Moscow in 1946 into a Russian Jewish family. His father was an engineer and his mother a nurse. He studied mathematics at Moscow University, and took a doctorate in 1984 on the “theory of optimising and decision making”. He went on to become a professor there, earning a worldwide reputation.

His commerical career began in the 1980s when he went into business importing computer software from the west, but it was the end of the Soviet Union that made him. As Communist controls crumbled, he saw a chance to exploit the difference in price between cars sold cheaply for export and those sold in the home market. He established the Logovaz car dealership, which allowed him to sell off Russian-made Ladas at a profit. Logovaz evolved into a mammoth financial and business conglomerate and made Berezovsky a multi-millionaire.

Berezovsky met Boris Yeltsin in 1993, and soon established a mutually beneficial relationship with the Russian president and his circle. He subsidised the publication of Yeltsin’s biography and established a strong friendship with Yeltsin’s daughter, Tatyana Dyachenko and his chief of staff Valentin Yumashev, winning himself a key role in Kremlin decision-making. In 1995, Berezovsky acquired a 49 per cent stake in the television channel ORT and bought the potentially lucrative Sibneft oil company for just $100 million.

Berezovsky came to public prominence in 1996 when Yeltsin, who had slumped to just six per cent approval ratings in the polls, was embarking on what seemed a doomed re-election bid. Berezovsky mobilised his fellow oligarchs to provide millions of dollars in finance and organised a ruthlessly professional campaign with rock concerts and glossy advertising which crippled the opposition and rescued Yeltsin from defeat, although it brought on two heart attacks.

The oligarchs extorted a heavy price for their support of Yeltsin. They received shares in the most valuable state-owned companies as security against loans they made to the state budget in an infamous “loans for shares” scheme. After Yeltsin won the election, these companies were put up for auction and the oligarchs divided them among themselves. In 1997 Berezovsky acquired Aeroflot. The same year, Forbes magazine named him the ninth most powerful entrepreneur in the world with a fortune worth $3billion.

Berezovsky effectively took control of an unhealthy and increasingly confused president, who awarded him a Kremlin job as deputy secretary of the Security Council.

Effectively, he became the Kremlin’s man dealing with the breakaway republic of Chechnya, where a ceasefire had been agreed after 20 months of war. He helped forge the deal that had Aslan Maskhadov elected as Chechen president and Russia promise economic aid, although his detractors claimed his real interest was in getting his hands on the region’s oil. Maskhadov himself later claimed that Berezovsky had helped to finance warlords Shamil Basayev and Khattab in their separatist campaign. In 1998 his contacts in Chechnya enabled him to secure the release of two British men held hostages by Chechen rebels.

His appointment as executive secretary of the Commonwealth of Independent States (CIS) — a loose league of 12 former Soviet republics — in 1997 carried little official weight but was another clear sign of his power. One Russian cartoonist depicted him as a black devil looking over the president’s shoulder.

It is hard to pinpoint the exact moment at which it all began to turn sour, but a raid by police on the offices of an obscure Moscow security firm in July 1998 marked a turning point. Among an arsenal of bugging devices, scanners and cameras, police found a library of video and audio cassettes reaped from years of snooping on top people, including members of Yeltsin’s family. The owner of the firm was Berezovsky. As a result of the raid, the bedrock of Berezovsky’s power — his access to the Kremlin — was shaken.

Details of the raid leaked onto newspaper front pages. Acting on instructions from the prosecutor general, Yuri Skuratov, police raided companies linked to Berezovsky. At first, the Yeltsin administration and its allies in the law enforcement agencies tried simply sacking Berezovsky from his Security Council post, and forcing the prosecutor-general to resign by leaking a lurid video of him having sex with two prostitutes. Extracts from the video, featuring Skuratov being orally pleasured, were shown on prime time television.

But the Russian parliament rallied behind Skuratov. He stayed in place, and launched an anti-corruption investigation. In 1999 an arrest warrant was issued for Berezovsky in connection with alleged profits skimming at Aeroflot, but was subsequently dropped.

Meanwhile Berezovsky had transferred his political allegiance to the up and coming Vladimir Putin, Yeltsin’s prime minister. Putin’s presidential victory in March 2000, was effectively secured during campaigning for the parliamentary elections of December 1999, when a ferocious smear campaign on ORT television effectively eliminated his two main rivals. In a series of popular prime time news shows, Moscow mayor Yuri Luzhkov was portrayed as a murderous conman, while gory footage of a hip operation was broadcast to demonstrate that the former prime minister Yevgeny Primakov (who had recently undergone surgery) was not up to the job. The parliamentary elections also saw Berezovsky elected as representative for the region of Karachevo-Cherkess, securing him immunity from prosecution.

The honeymoon with Putin was shortlived. During his election campaign, Putin gained popular support by promising to crack down on the oligarchs and in June 2000, he instigated criminal investigations against many of those who had flourished under his predecessor. Berezovsky was a particular target since he had used his media empire to criticise Putin over his handling of the war in Chechnya and the Kursk submarine disaster. In July 2000, he resigned from his seat in parliament in protest at “authoritarian trends” within Putin’s government.

In 2001, as investigations proceeded, Berezovsky fled to France, then to London, where he sought to reinvent himself as a champion of liberal democratic values. The irony did not go unremarked in Russia. Berezovsky professed to be immune to public cynicism about his motives. “I just hope to help people,” he said.

In 2002, the Russian authorities issued an arrest warrant on charges of money-laundering and illegal business activity. Berezovsky sought to resist moves to extradite him, claiming to be a martyr to an “utterly corrupt” legal system, and arguing, more persuasively, that his life would be in danger if he returned.

In 2004, rumours swirled that Berezovsky had helped to finance Ukraine's Orange Revolution.

Then, in 2006, Alexander Litvinenko, a former officer in the Russian security service who worked for Berezovsky, died after being poisoned with radioactive polonium at a London hotel. He accused Mr Putin of his murder.

Berezovsky had six children during his two marriages and one long-term relationship.

He had two children with his first wife, Nina.

He married his second wife, Galina Besharova, in 1991. The couple divorced in 2010, and in 2011 he paid her the biggest divorce settlement in history, believed to be worth hundreds of millions. They had two children.

He split from long-time partner Yelena Gorbunova, with whom he had two more children, in 2012.

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