The Fourth (Unity) Congress of the Russian Social Democratic Labour Party that took place in Stockholm, Sweden, from April 10-25 (April 23 to May 8), 1906. The Congress was attended by 112 delegates with the right to vote, who represented 57 local Party organisations and 22 delegates with voice but no vote. Other participants were delegates from various national Social-Democratic parties: three each from the Social-Democrats of Poland and Lithuania, the Bund and the Lettish Social Democratic Labour Party, one each from the Ukrainian Social-Democratic Labour Party and the Finnish Labour Party, and also a representative of the Social Democratic Labour Party of Bulgaria. Among the Bolshevik delegates were Mikhail Frunze, Mikhail Kalinin, Nadezhda Konstantinovna Krupskaya, Vladimir Lenin, Anat