By his time the kingdom must have reached the west coast, as he is said to have conquered the islands of Anglesea and Man.
The Decangi, owning the island of Anglesea (Ynys Fon) and the Snowdonian district; the Ordovices, inhabiting the modern counties of Denbigh, Flint and Montgomery; the Dimetae, in the counties of Cardigan, Carmarthen and Pembroke; and the Silures, occupying the counties of Glamorgan, Brecknock, Radnor and Monmouth.
When we turn to the British Islands we find, as we should expect, no traces of the Druids in England and Wales after the conquest of Anglesea mentioned above, except in the story of Vortigern as recounted by Nennius.
The coast-line of Anglesea and the Isle of Wight, but of no other islands, is included.
At the accession of William Rufus the domain of Gwynedd had been reduced to Anglesea and the Snowdonian district, and that of South Wales, or Deheubarth, to the lands contained in the basins of the rivers Towy and Teifi, known as Ystrad Tywi and Ceredigion.
The chief inlets are the mouth of the Dee, dividing Flint from Cheshire; the Menai Straits, separating Anglesea from the mainland; Carnarvon Bay; Cardigan Bay, stretching from Braich-y-Pwll to St Davids Head; St Brides Bay; Milford Haven; Carmarthen Bay; and Swansea Bay.
MENAI STRAITS, a channel of the Irish Sea, separating Anglesea from Carnarvonshire, N.
The Yorkist faction seems to have been strongest in the eastern portion of the Principality, where the Mortimers were all-powerful, but later the close connexion of the house of Lancaster with Owen Tudor, a gentleman of Anglesea (beheaded in 1461) who had married Catherine of France, widow of Henry V., did much to invite Welsh sympathy on behalf of the claims of Henry Tudor his grandson, who claimed the English throne by right of his grandmother.