born Sept. 3, 1859, Castres, France died July 31, 1914, Paris French socialist leader. He served in the Chamber of Deputies (1885-89, 1893-98, 1902-14) and at first adopted the ideas of Alexandre Millerand. After 1899 the socialists split into two groups, and Jaurès headed the French Socialist Party, advocating reconciliation with the state. In the newspaper L'Humanité, which he cofounded in 1904, he espoused democratic socialism, but when the Second International (1904) rejected his position he acquiesced. In 1905 the two French socialist parties united, and his authority continued to grow. On the eve of World War I, he espoused peace through arbitration and championed Franco-German rapprochement, which earned him the hatred of French nationalists, and he was assassinated in 1914 by a young nationalist fanatic. He wrote several books, including the influential Socialist History of the French Revolution (1901-07)