Is king Arthur a real monarch or just a legend?

It is a myth. ..King Arthur, legendary British leader, is said to have led the defense of Britain against the Saxon invaders in the early sixth century; and there's been many debates and disputes by modern historians over whether he did exist. ..According to one story , it's been said: "If ever England shall fall, Arthur shall return..He will draw Excalliber from the lake, and become Righteous Ruler of all England." ..It is believed by the Cornish people of Cornwall that the ruins of Tintagal Castle in Tintagal is the birthplace of King Arthur.