A New Source for mons Badonicus? Returning to the Irish life of Finnian of Clonard

Abstract

This paper examines a report describing conflict between Saxons and Britons in the Irish life of Finnian of Clonard. It connects this report to the battle at Llongborth, remembered in an early medieval Welsh poem, and to the siege of 'mons' Badonicus, reported by a variety of early medieval insular historians. Both battles have been linked to the legendary King Arthur. In connecting these battles to an entry in 'Anglo-Saxon Chronicle' and to the immediate context of Gildas' 'De excidio Britanniae', this article offers a date for 'mons Badonicus' in the early 480s and conjectures that the 'Age of Arthur', if historical, postdates the publication of 'De excidio'.