Sergey Fedorovich Oldenburg

Sergey Fedorovich Oldenburg (26 September 1863 – 28 February 1934) was a Russian ethnographer and activist in the Kadet Party.

In December 1917, a month after the October Revolution, Oldenburg met with Vladimir Lenin, the leader of the Revolution. Both men being sympathetic to the Assassins, they agreed that the Russian Academy of Sciences should work with the Brotherhood, granting use of several of the Academy's facilities to the them.