St. Eulogius was a Syrian by birth, and embraced young the monastic state in that country. The Eutychian heresy was then split into various sects, as it usually happens among such as have left the center of union. These, by their tyranny and the fury of their contests, had thrown the churches of Syria and Egypt into much confusion, and a great part of the monks of Syria were at that time become remarkable for their loose morals and errors against faith. Eulogius learned from the fall of others to stand more watchfully and firmly upon his guard, and was not less distinguished by the innocence and sanctity of his manners than by the purity of his doctrine.
Having, by an enlarged pursuit of learning, attained to a greet variety of useful knowledge in the different branches of literature, he set himself to the study of divinity in the sacred sources of that science which are the holy scriptures, and the tradition of the church explained in its councils and the approved writings of its eminent pastors. In the great dangers and necessities of the church he was drawn out of his solitude, and made priest of Antioch by the patriarch St. Anastasius. Upon the death of the patriarch John, Saint Eulogius was raised to that patriarchal dignity toward the close of the year 583. Our saint was obliged to make a journey to Constantinople, about two years after his promotion, in order to concert measures concerning certain affairs of his church. He met at court St. Gregory the Great, and contracted with him a holy friendship, so that, from that time, they seemed to be one heart and one soul. Among the letters of St. Gregory, we have several extant which he wrote to our saint. St. Eulogius composed many excellent works against various heresies. He died in the year 606.
(Adapted from Fr. Butler’s Lives of the Saints)