The Battle of Badon, also known as the Battle of Mons Badonicus, was purportedly fought between Britons and Anglo-Saxons in Post-Roman Britain during the early 6th century. It was credited as a major victory for the Britons, stopping the westward encroachment of the Anglo-Saxon kingdoms for a period.
The earliest known references to the battle, by the British cleric Gildas, was written c. 543-547. It is chiefly known today for the involvement of the man who would later be remembered as the legendary King Arthur. His name is not known, although the name under the form "Arthur" first appears in the 9th-century Historia Brittonum, where he is mentioned as having participated in the battle alongside the Brittonic kings as a war commander, though is not described as a king himself. Because of the limited number of sources, there is no certainty about the date, location, or details of the fighting apart from the result being a victory for the Britons.
Almost all scholars agree that this battle did take place. Gildas wrote within living memory of the battle (he claims to have been born in the same year it was fought). But being a moralist, he does not mention Arthur or the names of other British leaders who took part, nor does he provide the names of the Saxon leaders. Gildas also does not describe it as an actual open battle, but rather as a siege.
Historical accounts
Gildas
The earliest mention of the Battle of Badon appears in Gildas' De Excidio et Conquestu Britanniae (On the Ruin and Conquest of Britain). In it, the Anglo-Saxons are said to have "dipped <nowiki>[their]</nowiki> red and savage tongue in the western ocean" before Ambrosius Aurelianus organized a British resistance with the survivors of the initial Saxon onslaught. Gildas describes the period that followed Ambrosius' initial success: