Gregory of Nazianzus

Gregory of Nazianzus (Koine Greek: Γρηγόριος ὁ Ναζιανζηνός, romanized: Grēgórios ho Nazianzēnós, IPA: [ɣriˈɣori.os o nazi.anziˈnos]; c. 329 – 25 January 390), also known as Saint Gregory the Theologian or Gregory Nazianzen, was an early Roman Christian theologian and prelate who served as Archbishop of Constantinople from 380 to 381. He is widely considered the most accomplished rhetorical stylist of the patristic age. As a classically trained orator and philosopher, he infused Hellenism into the early Church, establishing the paradigm of Byzantine theologians and church officials.

Gregory made a significant impact on the shape of Trinitarian theology among both Greek and Latin-speaking theologians, and he is remembered as the "Trinitarian Theologian". Much of his theological work continues to influence modern theologians, especially in regard to the relationship among the three Persons of the Trinity. Along with the brothers Basil of Caesarea and Gregory of Nyssa, he is known as one of the Cappadocian Fathers.

Gregory of Nazianzus is a saint in both Eastern and Western Christianity. In the Catholic Church he is numbered among the Doctors of the Church; in the Eastern Orthodox Church and the Eastern Catholic Churches he is revered as one of the Three Holy Hierarchs, along with Basil of Caesarea and John Chrysostom. Along with them and Athanasius of Alexandria he is also regarded by the Catholic Church as one of the four Great Greek Church Fathers.

He is also one of only three men in the life of the Orthodox Church who have been officially designated "Theologian" by epithet, the other two being John the Apostle, and Symeon the New Theologian.