French radical politician. A leading parliamentarian of the inter-war period, Herriot was president of his party (1919–26, 1931–35, and 1945–56) and prime minister (1924–25, 1926, and 1932). As president of the chamber of deputies 1936–40 and a staunch republican, he challenged the legality of the 1940 parliamentary vote establishing the Vichy regime.
A graduate of the Ecole Nationale Supérieure, Herriot taught philosophy before becoming mayor of Lyon 1905–40 and 1945–57, and representing the Rhône department in parliament 1912–40 and 1946–57. Herriot combined internationalism (opposing Raymond Poincaré's 1923 occupation of the Ruhr) with social conservativism (distancing himself from Edouard Daladier's participation in the Popular Front alongside socialists and communists). Arrested by the Vichy authorities in 1940 and deported to Germany in 1944, he served again as president of the National Assembly 1947–54.