Abramovich's one time business partner and his early days business guru. Abramovich is said to have learnt his business and political networking skills from Boris Berezovsky. It is also said that, "At every stage of Berezovsky's rise, Abramovich was there, watching and learning." He is best known for his role as a Russian businessman, media tycoon and politician during the presidency years of Boris Yeltsin in the 1990s. He also served as deputy secretary of Russia's security council.