But when the pope’s eyes were opened, he sent the bishop Marinus to Constantinople to declare invalid what the legates had done contrary to, his instructions. For this Marinus was shut up in prison for thirty days. After his return Pope John VIII solemnly pronounced the anathema on Photius, who had dared to deceive and degrade the holy see, and had added new frauds to the old. Marinus renewed the anathema after he was elected pope (852). Photius denied the validity of his election, and developed an extraordinary literary activity.