This book seeks to refine the image of Gildas, a key figure of authority in the early medieval British church. It does so by examining his self-image as presented in surviving works variously dated to the fifth or sixth centuries, and subsequent images as developed by the reception of these works – the legacy of Gildas – up to the early eighth century. The purpose of this investigation is to clarify and reconcile these often-conflicting depictions in order to better understand Gildas. This reconciliation is important because the way we perceive Gildas – a rare beacon in a ‘dark age’ – is inextricably bound up in the way we perceive the Christian culture of the British Isles in the opaque period following the decline and fall of the western Roman empire. A Gildas that shines more brightly, this book argues, shines more light on the early Insular church and its place within the continental church.

When describing the Christian culture of Britain and Ireland in the fifth and sixth centuries, Gildas is an exceptional figure. This is not because of the particularity of his historical and religious vision, but rather because he is the only remotely contemporary Insular voice narrating a pivotal shift in the history of the British Isles – the period when the Roman province of Britannia and the political entities of the Picts and Scots began to evolve into the medieval nations of England, Scotland, Wales, and Ireland. The detail of this significant shift, bedevilled by enigmatic material evidence and limited textual sources, is not well understood. Gildas is, thus, an essential witness, and the way in which his historical and religious vision has been received by scholars has profoundly shaped perceptions of this hugely important, yet poorly documented, transition.

Gildas's unique history of the Christian culture of Britannia forms a discrete section in his most notable surviving text, the De excidio Britanniae or the Ruin of Britain. An open letter in three parts, Gildas denounces contemporary secular and church leaders of the former Roman province of Britannia in the context of corruption, civil strife, and partition with pagan powers.