Patriarch of that see from 580 to 607. He was a successful combatant of the heretical errors then current in Egypt, notably the various phases of Monophysitism. He was a warm friend of Saint Gregory the Great, corresponded with him, and received from that pope many flattering expressions of esteem and admiration. Among other merits the pope makes special mention of his defence of the primacy of the Roman See. Eulogius refuted the Novatians, some communities of which ancient sect still existed in his diocese, and vindicated the hypostatic union of the two natures in Christ, against both Nestorius and Eutyches. Baronius says that Gregory wished Eulogius to survive him, recognizing in him the voice of truth. It has been rightly said that he restored for a brief period to the church of Alexandria that life and youthful vigour characteristic of those churches only which remain closely united to Rome. Besides the above works and a commentary against the various sects of the Monophysites (Severians, Theodosians, Cainites, Acephali) he left eleven discourses in defence of Leo I and the council of Chalcedon, also a work against the Agnoetae, submitted by him before publication to Gregory I, who after some observations authorized it unchanged. With exception of one sermon and a few fragments all the writings of Eulogius have perished.