This is a ground-breaking volume. It advances our understanding of these important grammatical texts from medieval Wales in many ways, particularly to demonstrate that the neglected later versions have been modified by contact with contemporary grammatical scholarship in England. This volume is required reading for all those interested in these intellectual developments in this period.

Paul Russell, Professor of Celtic emeritus, Department of Anglo-Saxon, Norse and Celtic, University of Cambridge

In this first thoroughgoing assessment of the Welsh bardic grammars in more than a generation, Jacques shows us that the grammars from the outset represent active, intentional engagement with the Latin grammatical tradition, mined for tools suitable to accurate description of the Welsh language. Over the course of time, the grammars were revised, abridged, updated and excerpted to serve audiences ranging from beginning readers, to the literate elite, to poets, to performers, in an ongoing dynamic process adapting them to the cultural needs of each historical moment in turn.

Catherine McKenna, Margaret Brooks Robinson Professor of Celtic Languages and Literatures, Harvard University

This is a book for which we have been waiting a very long time. It is a compelling study of the medieval Welsh grammatical tradition from the earliest texts to the Renaissance – a huge achievement in itself. What is more, Jacques has added to that achievement the inestimable service of providing the first full, scholarly English translation of any of the Welsh bardic grammars. I am confident that we will see a great resurgence of interest in these fascinating texts as a result of the present study.

Professor Barry Lewis, School of Celtic Studies, Dublin Institute for Advanced Studies