Common Brittonic
Evidence from Welsh shows a great influence from Latin on Common Brittonic during the Roman period. This is particularly true of the Church and Christianity, which are nearly all Latin derivatives. Common Brittonic was replaced in most of Scotland by Gaelic. South of the Firth of Forth it was replaced by Old English (which later developed into Scots). Common Brittonic survived into the Middle Ages in Southern Scotland and Cumbria. Common Brittonic was gradually replaced by English throughout England. In the north of England, Cumbric disappeared as late as the 13th century. In the south, the Cornish was a dead language by the 19th century. There were some attempts to revitalize it, which have met with some success.