The SFIO became the leading party in the Popular Front, which also included the Radicals and Communists. After the Popular Front victory in the spring 1936 elections, Blum became France's first Jewish and first Socialist premier on 4 June 1936. Under his leadership, the government enacted sweeping social legislation, including the nationalization of leading banks and industries and the establishment of a 40-hour workweek and other worker benefits. Unfortunately, these changes came at precisely the time that Germany was cutting worker benefits and straining to rearm.
Blum failed to win centrist and rightist support for his programs, and the flight of capital abroad and foreign reverses, especially the failure to aid the Spanish Republic during the Spanish Civil War (under pressure from London), led to his undoing. Too late, he realized the need for France to rearm. After the Chamber of Deputies refused his request for emergency fiscal powers, he resigned as premier in June 1937, although the SFIO continued in the Popular Front coalition.
Arrested on the orders of the Vichy government following Germany's defeat of France in July 1940, Blum was put on trial in Riom in February 1943, along with other leaders of the Third Republic, and charged with responsibility for the French defeat. His spirited defense embarrassed the Vichy government and helped lead to the suspension of the trial. Taken prisoner by the Gestapo in 1943, he was held in both the Buchenwald and the Dachau concentration camps until his release at the end of World War II.
Blum returned to France as a respected elder statesman. He headed a caretaker government between 1946 and 1947 and secured aid from the United States to assist in the reconstruction of his nation. He then retired permanently to his estate at Jouy-en-Josas, although he continued to write for Le Populaire. Blum died there on 30 March 1950.
Blum, Léon. For All Mankind. Trans. W. Pickles. New York: Viking Press, 1946.; Colton, Joel G. Léon Blum: Humanist in Politics. New York: Alfred A. Knopf, 1966.; Dalby, Louise Elliott. Léon Blum: Evolution of a Socialist. New York: T. Yoseloff, 1963.; Grayson, Jasper Glenn. The Foreign Policy of Léon Blum and the Popular Front Government in France. Chapel Hill: University of North Carolina Press, 1962.; Lacouture, Jean. Léon Blum. New York: Holmes and Meier, 1982.