Beunans Meriasek is one of only two surviving medieval saints’ plays in the British Isles, making it of central importance for the study of early vernacular drama. The surviving manuscript was written in the Cornish language near Camborne in Cornwall at the beginning of the sixteenth century, commemorates a Breton saint, and is currently held in the National Library of Wales near the place of its discovery. This important text is therefore not only of interest to scholars of the Celtic languages, medieval drama, and the religious and cultural history of Cornwall—but also to all those in Cornwall, Wales and Brittany fascinated by their historical relationship.No new critical edition of Beunans Meriasek has been published since that of Whitley Stokes in 1872. Since then a great deal of additional information has come to light about its background, authorship, relation to medieval drama in general and the wider historical context. Dr Combellack is well qualified to explain this: her unpublished PhD thesis on the play was completed in 1984 and forms the foundation of this new work, although substantially updated and revised in the light of subsequent developments and discoveries. Also known for a performable verse translation of the play, the author has taken particular care here to provide a literal, highly accurate English version in parallel to the Cornish text. This will make the play accessible to those from other disciplines and indeed to all.