John became patriarch during the rule of Governor Mohammed Ismael Ibn as Sanadji in Jerusalem. Mohammed was one who demanded gifts be made to him on every occasion, gifts that were a major expense on the patriarchate. About this demand, Patr. John complained to El Hasan, governor of Ramleh. In 966, after having complained several times, Mohammed took revenge on John by stirring up the Muslim mobs against the patriarch. On a rampage, the mob descended on the Church of the Holy Sepulchre, setting it on fire, and causing its cupola to collapse. Then, the mob turned to the church on Mount Zion, which they also burned. The next day the mob continued its reign of destruction during which they found John hiding in the oil cistern of the Church of the Holy Sepulchre, and murdered him. Following his murder the mob took his corpse to the yard of the Church where they burned it.