The Celt still held half of Britain.

At the date of his birth the northern Welsh still retained their independence in Strathclyde; the Welsh proper still spread to the banks of the Severn; and the West Welsh of Cornwall still owned all the peninsula south of the Bristol Channel as far eastward as the Somersetshire marshes.

Beyond Forth and Clyde, the Picts yet ruled over the greater part of the Highlands, while the Scots, who have now given the name of Scotland to the whole of Britain beyond the Cheviots, were a mere intrusive Irish colony in Argyllshire and the Western Isles.
He lived, in short, at the very period when Britain was still in the act of becoming England; and no historical doubts of any sort hang over the authenticity of his great work, "The Ecclesiastical History of the English people." But Baeda unfortunately knows little more about the first settlement than he could learn from Gildas, whom he quotes almost _verbatim_.

He tells us, however, nothing of extermination of the Welsh.
"Some," he says, "were slaughtered; some gave themselves up to undergo slavery: some retreated beyond the sea: and some, remaining in their own land, lived a miserable life in the mountains and forests." In all this, he is merely transcribing Gildas, but he saw no improbability in the words.

At a later date, AEthelfrith, of Northumbria, he tells us, "rendered more of their lands either tributary to or an integral part of the English territory, whether by subjugating or expatriating[1] the natives," than any previous king.