Russia
In recent times, the oligarchs has been used to describe a small number of Russian businessmen who came to prominence under President Boris Yeltsin. They tended to achieve vast wealth by acquiring Government assets very cheaply during the privatisation process started by the Yeltsin government. The oligarchs came under fire for illegal activities at the time (including murders) and underpayment of taxes in the businesses they acquired.
Their defenders argue the companies they acquired were not highly valued at the time because they were still run on Soviet principles, with non-existent stock controls, huge payrolls, no financial reporting and scant regard for profit. They turned the businesses - often vast - around and made them deliver value for shareholders.
The most prominent oligarch is Mikhail Khodorkovsky. Others include Roman Abramovich, Boris Berezovsky, Vladimir Potanin, Vladimir Bogdanov, Rem Viakhirev, Vagit Alekperov, Viktor Chernomyrdin and the youngest Mikhail Fridman.