The Russian Mob was a significant criminal organization based in Gotham City.
Affiliates with Falcone
The Russian Mob was affiliated with the Falcone crime family, the most powerful criminal organization at that time. Its leader Nikolai, however, wanted to usurp Falcone's mob, in collusion with Fish Mooney.
Death of Nikolai
After Oswald Cobblepot told Sal Maroni that he knew where Nikolai and his thugs were, a group of mobsters led by Frankie Carbone attacked a warehouse owned by Nikolai. Nikolai was gambling with his fellow mobsters when the door of the warehouse blew up and the Italian mobsters shot the Russians; Nikolai was shot many times as seen by the condition of his corpse.
Gregor Kasyanov, Nikolai's lieutenant, then continues his boss's work in usurping Falcone by helping Mooney rob a vault where Falcone stashes some of his money and guns with the reluctant help of Ian Hargrove, an explosives expert that the mob broke out of prison. The police arrive however, but before they can arrest the Russians, a car bomb is set by Butch Gilzean blew up, killing the Russian Mob members present.