The factions emerged in 1903 following a dispute within the Russian Social Democratic Labour Party (RSDLP) between Julius Martov and Vladimir Lenin. The dispute originated at the 2nd Congress of the RSDLP, 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", derived from the Russian ('minority'), while Lenin's adherents were known as "Bolsheviks", from ('majority').