EISENSTADT, ISAIAH (Isay ; pseudonym: Yudin, Vitali ; 1867–1937), pioneer of the Jewish socialist labor movement in Russia; born in Vilna. He became a member of Populist Narodnaya Volya ("People's Will") circles in the 1880s and was imprisoned for revolutionary activities. He returned to Vilna and in 1889 joined the Social Democrats. A Marxist theoretician, Eisenstadt also proved an extremely able organizer among the Jewish workers in Vilna and in Odessa. In 1896 he was exiled to Siberia, remaining in prison there until 1901. After his release, Eisenstadt became one of the main leaders of the *Bund, his activities being suspended by frequent arrests; during the controversy within the party (1908–10) between those preferring the use of legal action and the "anti-legalists," Eisenstadt supported the latter. In the central committee of the Russian Social Democratic Workers' Party he endeavored to effect a compromise between the Mensheviks and Bolsheviks. After the Revolution of February 1917 Eisenstadt was active in Petrograd (Leningrad). He was elected vice chairman of the central committee of the Bund, and after its split with the Communists, became associated with the leadership of the Social Democratic Bund. He was subsequently imprisoned, and at the beginning of 1922 received permission to leave Soviet Russia. He reached Berlin, and continued his political activity among the Menshevik émigrés there and in Paris, gradually inclining to the leftist faction. His first wife lyuba eisenstadt-levinson (1866–1903), also born in Vilna, became a Social Democrat while a student in Geneva. She was arrested at the Russian border and imprisoned for three years. From 1890 she was active as one of the leading propagandists for the party among the Jewish workers in Vilna and Bialystok. She was imprisoned with her husband in Siberia from 1896 to 1901. She died on a visit to New York.
G. Aronson, in: J.S. Hertz (ed.), Doyres Bundistn, 1 (1956), 137–54; lnyl, 4 (1961), 249–52; Sotsialisticheskiy Vestnik, 17:14, 15 (1937), 1–4.