St Bede the Venerable wrote Historia ecclesiastica gentis Anglorum ("Ecclesiastical History of the English People"), in 731 AD.
Bede chronicled that the Saxons and Angles were led by Hengist (Hengest) and Horsa and that they arrived in Britain in 449AD at King Vortigern's invitation. Bede also noted that Ambrosius Aurelianus won his first decisive battle against the Angles at Badon Hills, in AD 493. Ambrosius Aurelianus is given as the Briton resistance leader, and there is no mention of Arthur in Bede.
Arthur did not appear in recorded history until circa 796 in a compilation by the monk Nennius, called the Historia Brittonum. In it, Arthur is said to be the "dux bellorum" at Mount Badon (Mons Badonicus), the last of 12 sucessful battles by Arthur.
It seems odd that Bede would not have named Arthur if he had won the battle of Badon. Bede does after all name Vortigern, Hengest, and Horsa. The account of fifth century Britain by Bede is based on Gildas, with some additions.Though he did not name them, Gildas did describe the individuals whom Bede called Vortigern, Hengest, and Horsa. Gildas did not ascribe the siege of Badon to any particular individual.
King Arthur in Literature