There is no specific birth date attributed to King Arthur. Legend says Arthur was based on a fifth or sixth century British warrior. While popular in mythology, there is no evidence to show that King Arthur was a real person.
Little is known about the warrior, who was thought to be a military leader affiliated with Rome. It is believed that King Arthur fought off an attack by the Saxons, which led to the legends. In written works by Celtic monk Gildas, the battle is mentioned, but there is no reference to any man named Arthur. Over time, the Arthurian story evolved into folklore and legend.