Lenin starts his history from the period preceding the revolution of 1905. He speaks about the formation of the 3 main classes: the liberals, the petty bourgeois, and the workers-revolutionaries.
In revolution 1905 the Soviet form of organization was formed. The revolution of 1905 was a good learning ground for all: the leaders and the parties. The workers were trying to lead the peasants.
In the period 1907-1910, the revolutionary party was broken. The leaders use this period to learn the lessons of the revolution past.
1910-1914 - years of rising in the workers movement. The Bolshevik faction unites legal and illegal methods of struggle, often working in reactionary unions, etc.
1914-1917 - the imperialist war. Leaders of the Second International were criticizing the Russian Social Democrats for cruelty of its internal struggles. But when the war struck off all legality, they were not able to organize an open exchange of opinions, while the Russian Social Democrats did that in Switzerland. In this exchange, the Bolsheviks criticized the right-wing social democrats and the centrists, followers of Kautsky. This was one of the main reasons for their triumph in the 1917 revolution.
February 1917 revolution in Russia. Mensheviks and Social-Revolutionaries show themselves as opportunists, lacking or betraying revolutionary principles.