Arthur or Arturius was never a king,I have searched the king lists for years no "King" Arthur. He was not welsh, The Mabinigoin never mentions Arthur, the only reference to Arthur was in the poem "Y Gododdin". A historical record of the Birtons battle at Catraeth (modern day Catterick) against the Anglo Saxons, another glorious defeat. The Gododdin or Votadinii had many connections with Gwynedd, in the 5thc ad Cunedda of Gogoddin emigrated south to help his Cymric brethern fight the Irish Pirates. Thus began a long assosciation with the Welsh. It has been written that many of the Gododdin annals were moved to Wales as the Anglo-Saxon conquest took hold.
In the history of Dal Riata (Modern Argyll) it states that they came from Ulster, settled at Dun Add and moved into the rest of Alba.Aedan Mac Gabran was Righ or King, he had five sons ,one of whom was called Arturius. the Dal riatins also controlled Manau-Gododdin whose chief town was Camelon nr Falkirk.His mother was Pictish, his sister in law was called Morganna and his wife was Anora.Loch Lomond was and still is referred to as "the Lake". Near Arrochar at Loch Long is a mountain called "The Cobbler" or Ben Arthur. In Edinburgh we have Arthurs seat. Just another strand to the argument.
"We are the last people on earth, the last to be free": Calgacus