Yes he did. King Arthur just didn't live at Tintagel or fight at Cadbury Castle. You wont find him in those Southern English places. They were awash with German speaking, sauerkraut munching, leiderhosen-wearing folks who were totally getting into the whole being Angles and Saxons thing. They loved it. You'll have to look a bit further North to find King Arthur.

Shock horror, go wash you mouth out!

The tour company I rode shotgun for down the far west of Cornywall made their bread and butter convincing Joe Public he was for real and would throw you off the top of Tintagel Island for saying that! :-)
It was rather embarrassing for me as the tourists would ask me and I would direct them back to the driver. I was there to show them around the real antiquities not to manufacture a story up!! Didn't go down too well :-)