There are several Italian authors of the Dark Ages known loosely as John the Deacon, and a google search will quickly find evidence that people get confused. The text that I am working on, BHL 6104, is a Life of St Nicholas of Myra, in Latin, translated by “John the Deacon”. I struggled with this, so I thought that these notes might help someone!
The first place to look is the Clavis Scriptorum Latinorum Medii Aevi Italiae (700-1000), or SCLMAI, edited by B. Valtorta and published by Sismel in Florence in 2006 in one volume. This lists most of the following figures, all of whom left literary works, under the name of “John” or “Giovani”, some of whom are relevant, and I’ve added some notes under each.
- Iohannes Aretinus, episcopus = Bishop John of Arezzo.
Bishop of Arezzo in the second half of the 9th century. In 875 at the request of Pope John VIII he was part of a mission of Charles the Bald to invite him to Rome for consecration. In July 877 he participated in a council in Ravenna called by the same pope. He died in the summer of 900. Author of a Latin translation of a Greek text on the ascension of Mary.
- Iohannes Canaparius, monachus.
A monk in the monastery of Sts Boniface and Alexius on the Aventine in Rome and author of the Miracula s. Alexii. Became abbot in 1002, and probably knew St Adalbert of Prague during his stay in Rome. Died 1004. Author of the Passio S. Adaberti martyris Christi.
- Iohannes Casinensis, monachus = John of Montecassino = John the Monk (of Montecassino). 9th century.
The CSLMAI says that nothing is known of him, except that he lived at the end of the 10th c., and wrote a Passio S. Iohannis martyris.
Articles at Treccani say: John the Deacon (or John of Montecassino, or Giovanni Imonide, latin Iohannes Hymonides). – Monk of Montecassino, historian (b. ca. 852 – d. before 882). Influential at the curia of John VIII, friend of Anastasius Bibliothecarius, he composed from archival material one of the best lives of Gregory the Great. It is very likely that he was involved with the Liber pontificalis; more questionable is the attribution to him of other works, among which the so-called Cena Cypriani. (This short note from Treccani; a much longer article with bibliography by Paolo Chiesa is here).
- Iohannes Cluniacensis, monachus (Salernitanus) = John of Cluny, or John of Salerno = John the Monk (of Cluny / Salerno). Also Iohannes Romanus; Iohannes Italus (!)
Born in Italy, probably in Rome, he met Odo of Cluny in 938 and became a monk. Two years later he accompanied Odo to Rome, where he was later appointed prior of the monastery of St. Paul. In 943 he moved to Salerno where he composed the Life of Odo, who had died in Nov. 18, 942. Author of Sententiae Morales super Iob, and Vita S. Odonis Abbatis.
- Iohannes Hymmonides Romanus, diaconus = John Hymmonides, or John Romanus = John the Deacon (of Rome).
The SCLMAI : Born around 825, a deacon of the church of Rome. After the death of Pope Nicholas I (Nov. 867) he was exiled by the emperor Ludovicus II. He became part of the entourage of Pope John VIII, and was connected to Anastasius Bibliothecarius and Gauderico di Velletri. He planned (in vain) to continue the Historia Tripartita of Cassiodorus, and Anastasius Bibliothecarius trabslated a Greek Chronographia Tripartita to assist him. He died around 880, certainly before 882. He might be the author of the life of Pope Hadrian II contained in the Liber Pontificalis. Author of the Cena Cypriani; Vita S. Clementis; Vita S. Gregorii Magni.
The confusion between this man and John of Montecassino is obvious.
- Iohannes Mediolanensis, presbyter = John of Milan = John the Priest.
8-9th century, hagiographer. Author of a single work on the Passio of the Virgin Mary.
- Iohannes Neapolitanus, diaconus (and see also Guarimpotus Neapolitanus) = John of Naples = John the Deacon (of Naples). 9-10th century. This is undoubtedly our author.
Hagiographer and translator, deacon on the church of S. Gennaro ad Diaconiam (=St Januarius) at Naples. He was a pupil of the priest Auxilius, active in Naples ca. 896. In 902 he took part in the translation of the relics of St Severinus to Naples, and in 906 in that of the relics of the martyr Sosius to the monastery of St Severinus of Naples. His works are characterised in the Neapolitan school of translation from Greek by their extreme freedom and formal elegance. He may be the same as Guarimpotus Neapolitanus, in which case Guarimpoto would have been his name before ordination. The date of his death is unknown. Author of: Acta XL Martyrum Sebastenorum; Acta S. Sosii; Gesta Episcoporum Neapolitanorum; Passio S. Maximi Cumanae; Translatio S. Severini Neapolim; Vita S. Euthymii Abbatis; Vita S. Nicolai. The Life of St Nicholas was made at the age of 20 or 25 at the exhortation of the monk Athanasius, who may perhaps be identified with the Athanasiuis sent to Misenum with John to look for the relics of St. Sosius. BHL 611-7 are epitomes of the work. (SCLMAI; Long article with bibliography by Luigi Andrea Berto at Trecani here)
- Iohannes Ravennas, archiepiscopus = Archbishop John of Ravenna. died. 929. Author of 7 works.
- Iohannes Venetus, diaconus = John the Deacon (of Venice). b. ca.940-945, d. after 1018. Not in the SCLMAI.
Author of the Chronicon Venetum, the oldest Venetian history. (Wikipedia article here).
We must also mention one further figure:
- Guarimpotus Neapolitanus = Guarimpoto of Naples. 9-10th century.
Translator and hagiographer. It is unclear whether he can be identified with “Guarimpotus Grammaticus”, author of the translation of the sermon of Cosmas Vestitor on the translation of relics of John Chrysostom; likewise with John the deacon of Naples, with whose works the author of the Passio Eustratii has strong stylistic affinities. The name of Guarimpotus appears only in the prologue of the Passio Eustratii, so all his works are uncertain to some degree. Author of: a lost Passio S. Blasii (possible remains in BHL 1380-1379, which may instead be by Bonitus Neapolitanus Subdiaconus); Passio S. Eustratii et IV sociorum in Armenia, BHG 646-646a, PG 116, 468-515, made at the request of Athanasius II, bishop of Naples in 875-898; Passio S. Febroniae; Passio S. Petri Alexandrini, BHL 6692-3; Vita S. Athanasii ep. Neapolitani; Translatio S. Athanasii ep. Neapolitani.
Out of these, three figures actually appear as “John the Deacon”; John Hymmonides, John of Naples, and in fact also John of Montecassino. Following the links reveals that our boy is in fact John of Naples, translator of more than one hagiographical work from Greek.
I also found that searching for “Giovanni Diacono” produced a lot of information and some excellent bibliography.
What I had not realised was that Naples, in the 6th-9th century, was actually part of the Byzantine Empire, as the Duchy of Naples. Its ruler held the titles of dux and magister militum. Originally dependent on the exarchate of Ravenna, it transferred to the supervision of the Byzantine governor of Sicily after the fall of Ravenna. But in practice it was rare for a Byzantine army to appear in Sicily, and Naples therefore remained largely independent. It was vexed by constant Lombard raids, which devastated the countryside. At other periods the Byzantine government sent Greek settlers to reinforce the Greek population. The majority of the people were Latin speaking. By around 840 the Byzantine rule had dissipated to nothing, and the Duchy ceased to feature the Byzantine emperor on its coins. All the same, this was a bilingual environment, and there was a school of translations into Latin; including the text that we are concerned with here, the Life of St Nicholas.