Common Brittonic
Common Brittonic was an ancient Celtic language spoken in Britain. It is also variously known as Old Brittonic, British, and Common or Old Brythonic. The language of the Celtic people known as the Britons, by the 6th century had split into the various Brittonic languages: Welsh, Cumbric, Cornish, and Breton. It is classified as a P-Celtic and Insular Celtic language.