The Mensheviks were a faction of the Russian socialist movement that emerged in 1904 after a dispute in the Russian Social-Democratic Labour Party between Vladimir Lenin and Julius Martov, leading to the party splitting into two factions, one being the Mensheviks and the other being the Bolsheviks. The dispute originated at the Second Congress of that party, ostensibly over minor issues of party organization. Martov's supporters, who were in the minority in a crucial vote on the question of party membership, came to be called "Mensheviks"