Szmul Artur Zygielbojm (1895-1943), leader of the Jewish socialist Bund in interwar Poland, was the son of Yosef and Henia Zygielbojm. He was the oldest of ten children: Feige (b. 1896), Israel (b. 1898), Moshe (b.1899), Chava (b. 1902), Chana (b. 1904), Pinhas (b. 1906), Faivel (b. 1908), Avraham (b. 1910), and Reuven (b. 1912).
During his years in Warsaw (1919-1935), Zygielbojm was a member of the Bund's Central Committee and served as Secretary of the Central Council of Jewish Trade Unions. From 1930 he also edited the Jewish Trade Unions' journal, "Arbeiter Fragen." In 1936 Zygielbojm moved to Lodz to head its Bund branch. Two years later he was also elected to the Lodz City Council. After the German invasion, Zygielbojm returned to Warsaw, where he helped organize the Bund underground. He also represented the Bund on the first Jewish Council set up in Warsaw. Fearing imminent arrest Zygielbojm fled to Belgium at the end of December 1939. After the Belgian collapse, he fled to France and then to the U.S. in September 1940. In March 1942 he was sent to London to join the National Council of the Polish Government-in-Exile, which had one other Jewish member, the Zionist, Ignacy Schwarzbart. In May 1942 Zygielbojm received one of the first reports to reach the West of the mass murder of Jews in Poland. From then on he devoted himself to the mission of arosing the conscience of the world to come to their rescue. On May 12, 1943, when he received word of the final liquidation of the Warsaw ghetto and the deportation of his wife and son, Zygielbojm committed suicide in public protest "against the indifference with which the world looks at the destruction of the Jewish world, looks on and does nothing to stop it."