Augustodurum, Beauce
An actual city in northwest France, Normandy, near the English Channel, founded as a Roman settlement in the first century BC. A Roman legion was stationed here and by the third century the city was surrounded by a wall. It was an important part of the coastal defense of the Roman Empire against the pirates of the region.
According to Geoffrey of Monmouth, the city was built by Bedivere’s great-grandfather. Bedivere was buried here after his death in the Roman war. The Alliterative Morte Arthure transfers this to Bayonne.
The city is famous for the Bayeux tapestry, depicting the Norman Conquest of Britain.
Source
Historia Regum Britanniae | Geoffrey of Monmouth, c. 1138
Roman de Brut | Wace, c. 1155