The Cappadocian Fathers, also traditionally known as the Three Cappadocians, were a trio of Byzantine Christian prelates, theologians and monks who helped shape both early Christianity and the monastic tradition. Basil the Great (330–379) was Bishop of Caesarea; Basil's younger brother Gregory of Nyssa (c. 335 – c. 395) was Bishop of Nyssa; and a close friend, Gregory of Nazianzus (329–390), became Patriarch of Constantinople. The Cappadocia region, in modern-day Turkey, was an early site of Christian activity. While these three men are typically discussed as the Cappadocians, Macrina, Basil and Gregory's sister, was significant in forming them theologically and in terms of their interpretation of how to live out Christian religious practice.
The Cappadocians advanced the development of early Christian theology, for example the doctrine of the Trinity, and are highly respected as saints in both Western and Eastern churches.