Saint Gregory of Nazianzus

Gregory of Nazianzus (c. 329 – 25 January 390) 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, infusing Hellenism into the early Church, establishing the paradigm of Byzantine theologians and church officials. Gregory made a significant impact on Trinitarian theology among both Greek and Latin-speaking theologians, and he is remembered as the 'Trinitarian Theologian'. Along with his brothers Basil of Caesarea and Gregory of Nyssa, he is known as one of the Cappadocian Fathers. 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.

He is also regarded by the Catholic Church as one of the four Great Greek Church Fathers. Gregory was considered a patron saint of the Kotromanić dynasty and the Kingdom of Bosnia during the first half of the 15th century. He is 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.