An attempt to put such principles into practice leads to the fact that at the Second Congress of the Russian Social Democratic Labor Party (1903) Lenin got into a personal quarrel with the leader of Menshevism Yuli Martov, and the Russian Social Democratic Labor Party – to a split into Bolshevik and Menshevik factions. Since Lenin did not succeed in transforming the entire Social Democratic Party on his own principles, he is taking a course to form his faction into a separate party, forming parallel party structures; thus, at the end of 1904, his supporters formed the Bureau of Majority Committees, in fact a parallel Central Committee of the still united Russian Social Democratic Labor Party. At the Fourth Congress of the Russian Social Democratic Labor Party (1906) in Stockholm, the Bolsheviks, despite their name, find themselves in the minority. The Fifth Congress of the Russian Social Democratic Labor Party (1907) in London was accompanied by a bitter struggle between the two factions.