As a doctor and a Marxist, Ulyanov sought to apply his medical training to the revolutionary struggle. During the Revolution of 1905 he provided medical aid to strikers in Simbirsk. He became a trusted cadre of the Russian Social Democratic Workers' Party and was a delegate to its 2nd Congress. He served as the representative of the Central Committee in Kiev. His duties carried him throughout Russia and Ukraine, first to Serpukhov, then to Feodosiya and Crimea.