We aren’t even sure King Arthur was real.
There almost was a King Arthur, though not the King Arthur everyone thinks of. Arthur was the older brother of King Henry VIII, but died before becoming King, hence Henry VIII.
I watched a documentary on the History Channel regarding whether the real King Arthur was a myth or real. Turns out their is evidence for a British ruler that may have been the man behind the myth. Quite interesting.
Arthur was real, just all the events surrounding him were exaggerated