In 1903, at the 2nd Congress of the Russian Social Democratic Labour Party in London, the party split into two wings: the gradualist Mensheviks and the more radical Bolsheviks. The Mensheviks believed that the Russian working class was insufficiently developed and that socialism could be achieved only after a period of bourgeois democratic rule. They thus tended to ally themselves with the forces of bourgeois liberalism. The Bolsheviks, under Vladimir Lenin, supported the idea of forming a small elite of professional revolutionists, subject to strong party discipline, to act as the vanguard of the proletariat in order to seize power by force.