a nationality in France, on the Armorican Peninsula. Population, about 1.1 million (1967 estimate). The Breton language survives in everyday speech, mainly among peasants and sailors, while French is the school, administrative, and literary language. The population is Catholic. The Bretons are descendants of the Britons, a Celtic tribe that moved from the British Isles in the fifth and sixth centuries, and of local Romanized Celts. The main occupations are fishing, oyster dredging, navigation, and agriculture.