They were formed by a split in the Russian Social Democratic Workers Party 
They were formed by a split in the Russian Social Democratic Workers Party and were first led by Martov. The Social Democratic Party was permanently split into two factions in 1912, and thereafter, this group was often divided by internal dissent. They sought to form a party of the masses, believed there was a necessary transition period before creating the Socialist state, and were willing to work with bourgeois elements to achieve their goal. For ten points, identify the Russian revolutionary party opposed to Lenin's Bolsheviks.
They were formed by a split in the Russian Social Democratic Workers Party and were first led by Martov.
Mensheviks