Peter the Deacon

Peter the Deacon (Pierre le Diacre) was the librarian of the abbey of Montecassino and continuator of the Chronicon Monasterii Casinensis, usually called the Montecassino Chronicle in English. The chronicle was originally written by Leo of Ostia. According to both Chalandon and Lord Norwich, Peter is a poor historian and writer, much inferior to Leo.

A descendant of the Counts of Tusculum, he was offered in 1115 to the monastery of Monte Cassino. About 1127 he was forced to leave the abbey and retired to the neighbouring Atina, seemingly because he was an adherent of the Abbot Orderisius. In 1137 he was allowed to return to Monte Cassino. That same year he appeared before Emperor Lothair II, then in Italy, on behalf of his monastery. The sovereign was so pleased with him that he appointed him his chaplain and secretary, and would probably have attached him permanently to his person had not Abbot Wibald considered Peter's return necessary to the abbey.

At Monte Cassino Peter became librarian and keeper of the archives, of which he compiled a register. Besides continuing the chronicle of Monte Cassino by Leo Marsicanus (or Ostiensis) from 1075 to 1138, he wrote several historical works: "De viris illustribus Casinensibus"; "De ortu et obitu justorum Casinensium"; "De Locis sanctis"; Disciplina Casinensis"; "Rhythmus de novissimis diebus".

Peter forged, under the name of Gordian, the Passion of St. Placidus. He is vain and occasionally untruthful, but an entertaining writer. His works are in Patrologia Latina, CLXXIII, 763-1144.