Name given to a faction of the Russian Communist grouping lead by Vladimir_Lenin.
Bolshevik is the Russian word for "majority", which distinguished the faction from the other Communist faction the Mensheviks (meaning "minority"). The term derives from the first congress of the communist party at which Lenin was able to persuade a majority to support him as leader of the party. Many commentators point out the difficulties presented to the Menshevik faction by getting lumbered with this name. In fact the Mensheviks were in the majority until the Bolshevik seizure of power in 1918.
The Bolsheviks were the more radical of the two factions and were distinguished from the Mensheviks by a belief in the need for a centralised hierarchy striving to achieve power, a refusal to co-operate with bourgeoise democratic government and in addition the cult of Lenin as a heroic leader.
Leon_Trotsky was initially a member of Mensheviks but in one of the key defections from that wing of the party lined up behind Lenin after the First Russian Revolution.