The Britons (*Pritanī, Latin: Britanni, Welsh: Brythoniaid), also known as Celtic Britons or ancient Britons, were the Celtic people who inhabited Great Britain from at least the British Iron Age until the High Middle Ages, at which point they diverged into the Welsh, Cornish, and Bretons (among others). They spoke Common Brittonic, the ancestor of the modern Brittonic languages.
The earliest written evidence for the Britons is from Greco-Roman writers and dates to the Iron Age. Ancient Britain was made up of many tribes and kingdoms, associated with various hillforts. The Britons followed an ancient Celtic religion overseen by druids. Some of the southern tribes had strong links with mainland Europe, especially Gaul and Belgica, and minted their own coins. The Roman Empire conquered most of Britain in the 1st century AD, creating the province of Britannia. The Romans invaded northern Britain, but the Britonnic tribes such as the Caledonians and Picts in the north remained unconquered, and Hadrian's Wall which bisects modern Northumbria and Cumbria became the edge of the empire. A Romano-British culture emerged, mainly in the southeast, and British Latin coexisted with Brittonic. It is unclear what relationship the Britons had with the Picts, who lived outside of the empire in northern Britain; however, most scholars today accept the fact that the Pictish language was closely related to Common Brittonic.