St Gregory of Nazianzen, one of the Fathers of the Greek Church, was born in Asia Minor; he was made a bishop and afterward Patriarch of Constantinople. He labored wonderfully against the Arians. His success drew on him the hatred of the enemies of the Faith. Finally, he resigned his See and retired to his native town, where he died in 390. As a champion of the Faith he was so well equipped, so strenuous, and so exact that he is called St. Gregory the Theologian.
His firmness restored the Faith of the Council of Nicea to Constantinople; he was however a man of gentle spirit and eminently poetic mind. Renouncing his bishopric he set his heart on the contemplative life and monastic discipline.
(Source: The New Roman Missal by Father Lasance)
Commentary: St. Gregory of Nazianzen was a contemporary of both St. Athanasius, Bishop of Alexandria, Egypt and St. Jerome. Sts. Gregory and Athanasius were battling the Arian heresy while St. Jerome was compiling the first of the Bible. St. Jerome completed his work in 397.