On the Ruin of Britain

by Gildas

"On the Ruin of Britain" by Gildas is a sermon written in Latin in the late fifth or sixth century. This fiery work condemns both secular and religious leaders whom Gildas blames for Britain's dire condition after Roman rule. Written as prophetic polemic rather than straightforward history, it remains one of the only surviving accounts from this shadowy period, penned by someone who lived through the events. The text includes references to the legendary Battle of Mons Badonicus and denounces five kings for their sins before turning its wrath upon the British clergy.