Gildas (fl. some time between c.475 and c.550). An important British cleric, Gildas is chiefly known for his tract On the Ruin of Britain. This work outlines some of the history of 4th- and 5th-cent. Britain as a study in divine judgement, which he expected to come to bear on the evil rulers of his own day. He is the only early author to provide an account of the first Saxon settlements in Britain. As such he has attracted much exegesis, often fruitless. The most certain thing his book shows is that he was a well-educated man with a sophisticated style.

James Campbell

Gildas British historian of the 6th century whose Latin work, De Excidio et Conquestu Britanniae, refers to the British victory over the Saxons at the Battle of Badon Hill (although he does not mention Arthur).