Answer:
King Arthur was a legendary British leader who led the defense of Britain against Saxon invaders during the 5th and 6th centuries. According to legends, he was the head of the kingdom Camelot and the Knights of the Round Table. He appears in a cycle of medieval romances, although it is not certain if the figure of King Arthur was based on a historical person.
The details of King Arthur's story are mostly composed of folkloric and literary inventions and his historical existence has been debated among modern historians. Arthur's rare historical background was discovered from various sources including Annales Cambriae, Historia Brittonum and the writings of the Gildas.