Léon Blum (lāôN´ blŏŏm), 1872–1950, French Socialist leader and writer. Well established in literary circles, he entered politics during the Dreyfus Affair and rose to party leadership. In 1936 he brought about the coalition of Radical Socialists, Socialists, and Communists in the Popular Front, which won an overwhelming electoral victory. This first Popular Front government, which he headed, inaugurated the 40-hour week, collective bargaining, and compulsory arbitration; it also reorganized and nationalized the Bank of France; and nationalized the munitions industry. Conservative opposition to Blum's fiscal measures forced his resignation (1937). Blum served as vice premier (1937–38) under Camille Chautemps, was briefly premier in 1938, and opposed the Munich Pact. Arrested (1940) by the Vichy government, his Jewish origins made him a prime defendant in the abortive war-guilt trial at Riom in 1942. Blum was imprisoned until the end of the war. After negotiating (1946) a credit agreement with the United States, he was again premier for a little more than a month in 1946–47, heading an active Socialist cabinet. The elder statesman of French Socialists, Blum gradually came to represent the moderate wing. His writings include For All Mankind (tr. 1946, repr. 1969).
See biographies by J. Colton (1966, repr. 1974) and J. Lacouture (tr. 1982).