Origins and Monastic Life
Eulogius was a Syrian by birth who embraced the monastic life at a young age. He was ordained a priest in Antioch by the patriarch Anastasius I and became the igumen, or abbot, of a monastery dedicated to the Mother of God in that city.
From this monastic and pastoral background he was raised about 580 or 581 to the patriarchal throne of Alexandria, succeeding John IV, and he governed the Egyptian church for roughly the next twenty-seven years.
Defense of Orthodox Doctrine
As Patriarch of Alexandria, Eulogius contended against the heresies still active in his diocese. He refuted the Novatianists, who continued to maintain communities there, and opposed the several Monophysite parties, among them the Severans, Theodosians, Gaianites, and Acephali.
Against both Nestorian and Monophysite errors he defended the hypostatic union of the two natures in Christ, and he composed eleven discourses in support of Pope Leo I and the Council of Chalcedon. He also wrote a work against the Agnoetae, a sect that held the human soul of Christ to be ignorant of some things, and submitted it to Pope Gregory I for approval. Most of his writings have since been lost; only a sermon for Palm Sunday and a few fragments survive.
Friendship with Gregory the Great
Eulogius is especially remembered for his friendship with Pope Gregory I of Rome, whom the Orthodox tradition knows as Gregory the Dialogist. By tradition the two met at Constantinople around 582, before either had reached the height of his office, and they maintained a correspondence in later years.
Several of Gregory's letters to Eulogius survive, including one of June 598 that describes the progress of the mission of Augustine of Canterbury among the English. Gregory held the Alexandrian patriarch in high esteem; later writers record that he valued Eulogius as a voice of truth.
Repose and Veneration
Eulogius reposed in the early seventh century, about 607 or 608, and was succeeded as patriarch by Theodore I. He is venerated as a bishop and confessor, his feast being kept on February 13. Because he belongs to the undivided Church before the later divisions of Christendom, he is honored in both the Eastern Orthodox and the Roman Catholic traditions.