Auguste Marie Joseph Jean Léon Jaurès, commonly referred to as Jean Jaurès (French: [??~ ??.???s]; 3 September 1859 – 31 July 1914), was a French Socialist leader.
Initially a moderate republican, he was later one of the first social democrats, becoming the leader, in 1902, of the French Socialist Party, which opposed Jules Guesde's revolutionary Socialist Party of France.
The two parties merged in 1905 in the French Section of the Workers' International (SFIO).
An antimilitarist, Jaurès was assassinated at the outbreak of World War I, and remains one of the main historical figures of the French Left.