Boris Berezovsky

Berezovsky (left) with Roman Abramovich in the 90s.

Boris Berezovsky was a significant figure during the presidency of Boris Yeltsin, serving as deputy secretary of Russia's Security Council in 1996 and later as executive secretary in 1998. He played a role in Yeltsin's reelection in 1996 by bankrolling his campaign and using his media influence. After Vladimir Putin came to power, Berezovsky became a prominent critic of the Kremlin and went into exile in Great Britain in late 2000. He was found dead by hanging in his London bathroom, ruled a suicide, in 2013.