A new source for Mons Badonicus? Returning to the Irish life of Finnian of Clonard

Stephen J. Joyce

Research output: Contribution to journalArticleResearchpeer-review


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'.
Original languageEnglish
Pages (from-to)31-46
Number of pages16
JournalAustralian Early Medieval Association. Journal
Publication statusPublished - Nov 2019


  • mons Badonicus
  • Llongborth
  • Gildas
  • Finnian
  • Geraint
  • Arthur

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