Venerable John of Cathares the Confessor

John of Cathares was a ninth-century Byzantine monastic who served as abbot of the Kathara (Cathara) Monastery in Bithynia, in Asia Minor. The monastery, situated near Nicaea, had been established in the sixth century during the reign of the emperor Justin. As superior of this community John became a leading figure in the resistance to the renewed iconoclasm of the early ninth century, and the Church commemorates him as a confessor of the faith on April 27.

His prominence belongs to the period of the second iconoclast controversy, when the veneration of icons was again suppressed by imperial decree. Because he upheld and defended the veneration of the holy icons, John suffered repeatedly at the hands of the iconoclast emperors, named in the tradition as Leo and Theophilus. According to the surviving accounts he was repeatedly exiled and endured harsh treatment, and the anchor tradition records that he was a co-worker of Saint Theodore the Studite, the foremost monastic champion of the icons in that generation.

John reposed in exile about the year 832, having held to the veneration of icons throughout the persecution. He is honored as a venerable monastic and confessor, and his memory is kept in the Orthodox menaion on April 27.