Breton

Breton is a Celtic language spoken in Brittany, France. Breton is a Brythonic language, descended from the Celtic British language brought from Great Britain to Armorica by migrating Britons during the Early Middle Ages. Like the other Brythonic languages, Welsh and Cornish, it is classified as an Insular Celtic language. Breton is most closely related to Cornish, as both are thought to have evolved from a Southwestern Brythonic protolanguage. The other regional language of Brittany, Gallo, is a langue d'oïl derived from Latin and is consequently relatively close to French. Wikipedia