Marxist revolutionary party that preceded the Communist Party of the Soviet Union. Founded in Minsk in 1898, it held that Russia could achieve socialism only after developing a bourgeois society with an urban proletariat. The party split in 1903 because of the argument between the Bolshevik wing, led by Vladimir Ilich Lenin, and the Menshevik wing, led by L. Martov, over Lenin's proposals for a party composed of professional revolutionaries. Party members were active in the Russian Revolution of 1905. In the turmoil of the Russian Revolution of 1917, the Bolsheviks broke completely with the Mensheviks and changed their name to "Russian Communist Party (Bolshevik)