Mons Badonicus

…great victory was won at Mons Badonicus (a site not identifiable) toward 500: now it was Saxons who emigrated, and the British lived in peace all through the first half of the 6th century, as Gildas records. But in the second half the situation slowly worsened.

…victory at a place called Mons Badonicus, as yet unidentified. Thenceforward for more than a generation the invaders were confined to the southeastern coastlands which they had occupied in the earlier phases of the war. Many of them returned to the continent and obtained land for settlement from the kings…