Culture and language have been important concerns of politics and public policy in France since the ancien regime. In a country marked historically by provincial particularism, the process of "nation building" has been associated with the promotion of linguistic unity. During the Third Republic, that unity was threatened by the cultural and linguistic diversities within the Hexagon, a threat that was met by the creation of a centralized national school System. Today, linguistic unity, and by derivation the sense of national identity, is challengedfrom below by the revival of ethnoregional consciousness, and front above by progressive cultural Integration associated with the European Union and the global culture of technology and trade, which is dominated by the English language. Furthermore, the mass Immigration of the postwar years has introduced an additional threat to the monopoly of French. This paper examines a variety of official responses to these challenges, from selective policies of cultural pluralism to language requirements for citizenship, the officialization of the French language, attempts to prevent the "pollution" of the language, modalities for the use of French in science and the media, and the promotion of Francophonie outside France.