This critical edition of the classic Celtic text Trioedd Ynys Prydein has long been established as the standard. Based on a full collation of the most important manuscript sources, the earliest of which date to the thirteenth century, this edition presents the full Welsh text accompanied by English translations and extensive notes, along with four detailed appendices.

The Trioedd Ynys Prydein, or Triads of the Isle of Britain, form a series of texts which commemorate the names of traditional heroes and heroines and would have served as a catalog of the names of these heroic figures. This new edition is thoroughly revised and features a new preface by Morfydd Owen. It will be essential reading for Celticists and for those interested in early British history and literature and Arthurian studies.