I had a grad course in King Arthurian lit and we delved into the theories about the historical character. He is believed to be the son of a retired Centurian and learned Roman warcraft from him. He was probably alive during the late 400's and the earliest reference to him is from a Welsh poem written about 600. The epic poem describes 15 battles with the final victory on Mt. Baden. My favorite was one fight that included Artur, Merthyn, and Conan as survivors. All that Lancelot and Gwenivere love stuff was added by the French after 1000 a.d. After the Roman legions left, he was supposed to have kept the barbarians out during a 40 year reign, but after he died Vortigern invited the Saxons over to help against the Picts, but that didn't work out too well. Sorry, as a former history teacher, I love this stuff.