I've been doing some online reading about the legends surrounding King Arthur and his knights, as well as some reading about medieval Welsh history. From my understanding, during the time period King Arthur may have actually been around (I think 6th century or so?), there would have been no "knights" in Wales or other British regions like Cornwall.
My question is, was there ever a period in Welsh medieval history when the landed gentry or aristocracy of Wales would have included men calling themselves knights? For example, would there be examples of "Sir Such-and-such the Welsh knight?" If so, why did they start calling themselves knights and adopting this system of identification/status? Would they have adopted it from the English?
Follow-up question: When did the legends surrounding Arthur start referring to him as a "King" and his followers as "Knights?" Did it start with Geoffrey of Monmouth? I read Nennius's Historia Brittonum recently and if I recall correctly it referred to Arthur as something like "the soldier" or "war-band leader."