Valle d’Aosta street signs are bilingual (French and Italian) and almost all place names and local surnames are French in origin.

The origins of Valdostane bilingualism date back to 25BC, when the Romans founded Augusta Praetoria and began the latinisation of the natives – the Salassi. In 575, Pont-Saint-Martin became the border with the Franchi kingdom and Valle d’Aosta was positioned beside the kingdom of Bourgogne (a Gaul-Roman linguistic area), where Latin evolved into French-Provencal (Patois, still spoken today) and, starting from 1200, was gradually replaced by French as the written language.

In 1561, Duke Emanuel Filiberto of Savoy adopted French to replace Latin for all the public acts in the duke’s kingdom. From the 17th century, French was taught in the Collège Saint-Bénin in Aosta and in country schools, to the extent that at the end of the 19th century, the illiteracy rate was almost non-existent. In 1860, with the annexing of Savoia to France, Valle d’Aosta was the only French territory in Italy. The spreading of the Italian language began and reached its peak during the 20 years of Fascism which banned the use and teaching of French and saw the systematic translation of place names into Italian.

In 1948, special statutes of autonomy sanctioned parity between the Italian and French languages in Valle d’Aosta. In addition to Italian and French, in some municipalities in the Lys valley the Walser population speak the German-based dialects, Titsch and Toitschu.