When Bede published his Ecclesiastical History of the English People in 731, he included in his preface this famous comment on the languages in use in his own day. In dovetailing Britain’s linguistic complexity into the biblical patterning of the story he was about to relate, he betrayed his firm belief in the superiority of Latin as the language of Roman Christianity and of literate education. Implicit within Bede’s conspectus is a narrative of fundamental significance: the demise of Latin as the signal of Britain’s place within the Roman Empire, and its transformation into an elite schoolroom language necessary for a ‘religion of the book’, Christianity. In the course of this seismic linguistic shift, the universalizing features inherent within Christianity interacted with local particularities of language, politics and identity in exceptionally creative ways which transformed the cultural landscape. As will rapidly become clear, Ireland is deeply implicated in that British story: the purpose of this survey is to sketch the framework for these interconnected literary histories.