Bishop of Mantua in 1174, replacing a bishop removed for transgressions in office. In 1177, his predecessor repented, returned, and requested the return of his see. John asked permission to resign, return the mitre to the previous bishop, and return to his life as a hermit. The request was granted, and John transferred to Vicenza, Italy.
John was murdered by a man who had embezzled Church funds, and whom John was reprimanding. As John died working for the Church, and correcting a sinner, he is considered a martyr.
For All The Saints, by Katherine Rabenstein Catholic Online Book of Saints, by the Monks of Ramsgate Our Sunday Visitor's Encyclopedia of Saints, by Matthew Bunson, Margaret Bunson, and Stephen Bunson