Drawing on historical documents, legends, archeology and literature, this history describes the disintegration of Roman Britain that reached a climax in the decades after the Britons overthrew Constantine's government and were refused Roman rule. Beginning with the weakening of Roman Britain, the author chronicles the breakdown of the empire's social, political and economic order and the re-emergence of British political, economic and social structure as well as a parallel development among the Germanic invaders. The roles of religion, disease, the military, the Irish and the Picts during the 4th through 7th centuries are examined. This study synthesizes advances in post-Roman studies since Leslie Alcock's 1971 classic Arthur's Britain.