This volume presents an edition of a hitherto unpublished Old French Life of Saint Agnes, ms. B.N. Fr. 1553, accompanied by a study of the language and dialect of the poem. It presents a mixture of Picard and Francian forms, and linguistic evidence points to the middle of the thirteenth century as the time of composition. The Introduction reviews the scholarship dealing with the origin and growth of the St. Agnes legend. Appendices present for the first time four other versions of the legend: another Old French version preserved in the Bibliotheque Inguimbertine, ms. 106; an Anglo-French version by Nicole Bozon, preserved in ms. Cotton, Domitian XI, of the British Museum; an Irish version, ms. 23L29 of the Royal Irish Academy; and two Old French prose versions. A further section of the book studies some eleven versions of the legend in the vernacular languages of mediaeval Western Europe. Philologists, hagiologists, and students of mediaeval literature will find this a work of unusual importance.