Bund, Jewish socialist political movement founded in Vilnius in 1897 by a small group of workers and intellectuals from the Jewish Pale of tsarist Russia. The Bund called for the abolition of discrimination against Jews and the reconstitution of Russia along federal lines. At the time of the founding of the Russian Social-Democratic Workers’ Party (1898), the Bund was the most effective socialist organization in the country. Its determination to be the sole representative of Jewish workers conflicted with Lenin’s plans for a centralized party. In 1903 the Jewish leaders walked out of the second Congress of the Russian Social-Democratic Party. After rejoining the Social Democrats in 1906, they generally supported the Mensheviks. In April 1920 the Bund divided into two groups: the majority merged with the Communist Party while the minority, led by Rafael Abramovich, maintained its separate identity until suppressed by the Bolshevik government. The Bund was active in Poland between World War I and World War II.