The Breton language is Brittonic, not Gaulish, though there may be some input from the latter, having been introduced from Southwestern regions of Britain in the post-Roman era and having evolved into Breton--still partially intelligible by modern Welsh and Cornish speakers.
The Breton language is Brittonic, not Gaulish, though there may be some input from the latter. They brought with them their Brittonic language, which evolved into Breton--still partially intelligible by modern Welsh and Cornish speakers.