The Bolsheviks were a radical, far-left, and communist political faction and party in the Russian Empire that eventually successfully overthrew the Kerensky Provisional Government in the 1917 Russian October Revolution under the leadership of Vladimir Lenin.
The Bolsheviks arose from a 1903 factional schism in the Russian Social Democratic Labor Party, resulting in disagreement between Lenin and Julius Martov about the future of the party. Those who followed Lenin soon declared themselves the Bolsheviks (derived from the Russian for 'majority') while Martov's followers were termed Mensheviks ('minority'). In 1912, the Bolsheviks split entirely from the Mensheviks, forming their own political party, which became the driving force behind the 1917 revolution. Despite their name, the Bolsheviks were a much smaller and less influential party than the Mensheviks until the second half of 1917.
Joseph Stalin systematically executed most of the surviving Bolsheviks in 1937.