Antipope 997-998; d. probably in 1013. After the death of John XV, Bruno, a relative of Otto III and his chaplain, was raised through the royal influence to the papal throne as Gregory V, and crowned on 3 May, 996. On 21 May the new pope placed the imperial crown on the young King Otto III in Rome. After Otto's departure the patricius Crescentius and his followers rose against the pope, and in September, 996, drove him out of the city. In the following May (997) Archbishop John Philagathus of Piacenza, who had returned shortly before from a mission to Constantinople whither he had been sent by Otto III, was made antipope by Crescentius. John was a native of Rossano in Calabria, at that time a part of the Byzantine Empire. He became a monk and was closely connected with Empress Theophano, through whose influence he received the Abbey of Nonantola from Otto II. He was the godfather of the imperial Prince Otto, afterwards emperor. After the death of Otto II he remained the trusted adviser of the empress dowager who, in 988, promoted him to the episcopal See of Piacenza, raised for him to an archbishopric, though later restored to its original rank. At the court of Otto III he retained his influential position. The king sent him at the end of 995 to Constantinople to arrange a matrimonial alliance between the sovereign and a Byzantine princess. Notwithstanding this proof of favour on the part of the imperial family, John allowed himself on his return from Constantinople to be won over to the projects of Crescentius, who wished through him to bring about an alliance with Byzantium against the German Emperor. St. Nilus of Rossano, the famous abbot and a compatriot of John, sought to dissuade him from the usurpation of the papal throne, but without avail.

At the Synod of Pavia held by Gregory V at Pentecost, 997, Crescentius was excommunicated, and in July the pope issued a decree bringing Piacenza once more under the jurisdiction of the Archbishop of Ravenna. In the following winter Otto III returned to Italy at the head of an army, and in February, 998, entered Rome, while the antipope fled, and Crescentius entrenched himself in the Castle of Sant' Angelo. John XVI was captured by the imperial soldiers, deprived of his sight, and, his nose and ears having been mutilated, was brought in this condition to Rome. At the Lenten Synod of 998, held shortly after in Rome, Gregory V formally deposed the antipope, who, at the intercession of St. Nilus, was removed from prison to a monastery. When, in spite of all this, John again appeared before Gregory in episcopal robes, these were torn from him, and he was led through the streets of Rome on an ass amid the popular derision. According to the unreliable "Vita" of St. Nilus, he was thrown back into prison; while other sources relate that he was again confined in the monastery, where he died. The "Annales Fuldenses" record his death under date of 2 April, 1013. At Easter, 998, Otto III took the Castle of Sant' Angelo, and on 29 April Crescentius was beheaded.

Letters of the Byzantine ambassador Leo to Otto III in Sotér, XV (1892), 217 sqq.; JAFFÉ,Regesta Rom. Pont., II (2nd ed.), 495 sq.; LANGEN,Gesch. der röm. Kirche, III, 385-7; HEFELE,Conciliengesch., IV (2nd ed.), 650 sq. See also the works under II and III and on the history of Rome given under XIII.

J.P. KIRSCH