In Roman times the eastern half of the county formed part of the territory of the Silures, a pre-Celtic race, whose governing class at that time probably consisted of Brythonic Celts.
78-82 Agricola, carrying the Eagles of Rome beyond the line of the historical border, encountered tribes and confederations of tribes which, probably, spoke, some in Gaelic, some in Brythonic varieties of the Celtic language.
That they were non-Aryan, the theory of Sir John Rhys, seems improbable; for the non-English placenames of Scotland are either Gaelic or Brythonic (more or less Welsh), and the names of Pictish kings are either common to Gaelic and Welsh (or Cymric, or Brythonic), or are Welsh in their phonetics.
(2) The Brythonic or Brittonic 1 group, comprising Welsh, Breton and Cornish.
Gaulish, which was supplanted in France by Latin, had p, as in petor-ritum, " fourwheeled car," and is thus allied to the Brythonic group; but it is believed that remains of a continental Celtic qu- dialect appear in such names as Sequani, and in some recently discovered inscriptions.