This book is a landmark publication in the field of Early Irish History. Working from the fact that Ireland, in the period c.AD 400 to c.AD 1000, produced a massive body of literature, in a wide variety of genres and in two languages, Irish and Latin, that was far more extensive than in any other country in Europe, the author offers a context for the ‘communities of learning’ that produced such literature. Previous writers have struggled to explain how a society situated at the very edge of the known world could have done such a thing. Not the least of Elva Johnston’s achievements is to force a rethink of such underlying perceptions. Rather than viewing Ireland as an isolated and backward intellectual desert, for her ‘it is useful to see the island as a frontier-zone, comparable to other Roman frontiers’ (p. 11), and to see the evolution of Irish literacy and literate elites against the backdrop of Roman Frontier Studies. Though Ireland never suffered the traumatic consequences of barbarian invasion and the fall of Empire, Johnston argues nevertheless that there was much more than trading and raiding, or colonizing and slaving involved; she would see a much more profound influence at work: ‘the culture of early Christian Ireland is incomprehensible outside of the Late Antique context’ (p. 25).