Translated into English for the first time -- the full record of the congress which marked the birth of Bolshevism. During its month-long proceedings, held in secret in Brussels and London, Lenin and his supporters forged a cast-iron basis for the split with Menshevism. This verbatim record, later analyzed by Lenin in 'One Step Forward, Two Steps Back', shows how his stand on Paragraph 1 of the rules grew out of an intransigent struggle for Marxism against all bourgeois tendencies. In establishing democratic centralism as the organizing principle of the revolutionary party, this stand drew out al the opposition in the congress to building such a party. Here the dividing lines of the Russian Revolution were drawn -- fourteen years later, the Mensheviks took their stand on the side of world imperialism, in rabid opposition to the revolution; while the Bolsheviks led the working class to seize power and establish the first workers' state in history. This record of the 1903 struggle contains vital lessons for the struggle to build the revolutionary party today.