The Arthurian legend begins with the Welsh cleric Geoffrey of Monmouth (c. 1100 - c. 1155 CE). Earlier history writers such as Gildas, Bede, and Nennius had already established the existence of a British war-chief who defeated the Saxons at Badon Hill long before Geoffrey wrote his own account but none of them would imagine the king so brilliantly or choose to develop history into legend. In the beginning...