King of the Huns.
Three generations before Arthur, he allied with King Melga of the Picts and King Gillomaur of Ireland to invade Britain. He plagued Kings Maximus and Gratian before he was driven away for good when Constantine, Arthur’s grandfather, arrived from Brittany to assume Britain’s throne.
Historia Regum Britanniae | Geoffrey of Monmouth, c. 1138
Roman de Brut | Wace, c. 1155