Gregory of Nazianzus (, "Grēgorios ho Nazianzēnos"; c. 329 – 25 January 390), also known as Gregory the Theologian or Gregory Nazianzen, was a 4th-century Archbishop of Constantinople, and theologian. 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 of Nazianzus was the patron saint of medieval Bosnia before the Catholic conquest when he was replaced by Gregory the Great.