Arthuret
Welsh: Arderydd
Arfderydd
The Latinised form of the Welsh word Arfderydd.
This is the schene of a battle, about the year AD575, in which Rhydderch Hael defeated Gwenddolau. Myrddin is said to have taken part in the battle, traditions vary as to the side he was on, and supposedly went insane because of a vision he saw in the sky there.
Despite the name, it is unrelated to Arthur.