John the Deacon (Neapolitan historian)

John the Deacon (d. after 910) was a religious writer and deacon, or head of a diaconate at the church of Saint Januarius in Naples. He flourished towards the end of the ninth and the beginning of the tenth century, and from his writings appears to have been a very learned and accomplished cleric. He wrote several historical works, important sources of information for the history of his time.

He first wrote a continuation of the diocesan chronicle of Naples (Gesta episcoporum Neapolitanorum), begun by another cleric, but which he brings down from 762 to 872. He makes use of both written and oral tradition, and contributes from personal knowledge. The narrative is graphic and spirited, and impresses the reader as a frank and accurate story. He also wrote a history of the translation in the fifth century of the remains of St. Severinus, the Apostle of Noricum, from the Castellum Lucullanum in the Bay of Naples to a new monastery within the city. This work contains the important account of the destruction of Taormina in Sicily by the Saracens under Ibrahim, and of the martyrdom of Bishop Procopius. When in 910 the relics of St. Sossius, a companion of St. Januarius, were transferred from the ruined Miseno to the same monastery at Naples, John wrote a history of St. Januarius and his companions, in which as an eyewitness he describes the aforesaid transfer. A biography of St. Nicholas of Myra is not by this John but by another author of the same name.