"MOSCOW — Boris A. Berezovsky, once the richest and most powerful of the so-called oligarchs who dominated post-Soviet Russia, and a close ally of Boris N. Yeltsin who helped install Vladimir V. Putin as president but later exiled himself to London after a bitter falling-out with the Kremlin, died Saturday."
http://www.nytimes.com/2013/03/24/world/europe/boris-a-berezovsky-a-putin-critic-dies-at-67.html?_r=0