The work is the first volume of the critical edition of the Vita Gregorii I papae (BHL 3641-3642), written by John the Deacon at the end of the 9th century. The main part of the volume is the census and the catalogue of the 148 manuscripts of the Vita which are the direct tradition. The appendices, at the end of the book, outline the status quaestionis of the Vitae on Gregory the Great: the manuscripts used in the oldest editions are identified (from the princeps in 1551 to that by Benedictins of St. Maur in 1705); a list of the lost manuscripts and of those erroneously identified in catalogues; a handlist of the manuscripts with abbreviationes of the Vita Gregorii by John the Deacon or rewritings with interpolations by Bede or Paul the Deacon.
