Brittany was called Armorica during the Gallic and subsequent Roman eras. It was not until the Migration Period in the fifth century, when large numbers of Britons fleeing Britain—mainly Cornish—migrated there, that it acquired the name Brittany, meaning Little Britain. They brought with them Insular Celtic culture.
It was called Insular Celtic culture to distinguish it from Continental Celtic culture. The ancient Celts had no capital; they existed for a long time in the form of tribes, and their expansion across Europe could be understood as tribal migration.
The Gaelic spoken by the Irish also belonged to the Celtic languages, but it differed from the dialect spoken by the Bretons. Breton was closer to Cornish and Welsh, which likewise belonged to the Celtic languages.
The clergy had likely spent considerable time and effort figuring out what those migrating Celts were saying. The Druids left no written records, relying entirely on oral transmission. Most Irish liked to call places they loved "cattle pens beneath the sun," while Britain had been called "the goddess's space" (clas myrddin) even before it was inhabited. The word "myrddin" could now be used as a personal name; in Welsh, it meant eagle. During the Hundred Years' War, there was once a man called the Eagle of Brittany. His name was Bertrand du Guesclin, eldest son of Robert du Guesclin, lord of Broons. Yet his parents disliked him because of his ugly appearance.
Bertrand's parents often secretly wished that the child would die at once, or drown in a rushing stream. They even called their son a wild child, a fool, or an ugly monster. Thus, Bertrand received almost no parental affection from an early age. He had no interest in reading or writing, and what he loved most was gathering the nearby children in Brocéliande Forest