Common Brittonic

Common Brittonic is the name given to the Celtic language spoken in Great Britain from the later centuries BC until c. 500 AD. It would ultimately evolve into the modern Brittonic (or Brythonic) languages Welsh, Cornish and Breton (via Britons who took refuge in what is now Brittany), as well as Cumbric and Pictish, both of which have been extinct since medieval times. In modern-day England, Brythonic languages were largely replaced by Old English starting in the mid-5th century, and by Goidelic Celtic in much of Scotland.