SFIO

SFIO stands for Section Française de l'Internationale Ouvrière, the French socialist political party founded in 1905 from the merger of several socialist groups aligned with the Second International. It served as the main vehicle for French social democracy in the early 20th century, with leaders such as Jean Jaurès and, later, Léon Blum. The party promoted parliamentary democracy, social reform, and welfare-state policies within the framework of the French Third Republic.

In 1920, at the Tours Congress, a significant faction decided to join the Communist International, forming the French Communist Party (PCF). The remainder continued as the SFIO and remained affiliated with the Second International.

The SFIO participated in government on multiple occasions, most notably Léon Blum’s Popular Front ministries in 1936-1938. After World War II, the party was a leading force in the Fourth Republic, contributing to postwar social legislation and state modernization. Throughout the 1950s and 1960s its influence waned as Gaullism and other left currents grew.

In 1969 the SFIO renamed itself the Parti Socialiste (PS) as part of a modernization effort. Under François Mitterrand, who led the party in the late 1970s and early 1980s, the PS won the presidency in 1981 and marked a new era for French left politics. The SFIO name is now primarily of historical significance, with the party’s modern successor continuing as the Socialist Party (Parti Socialiste, PS).