Sts. Basil the Great and Gregory of Nazianzus
Two of the three Cappadocian Fathers, the other being Basil’s brother, Gregory of Nyssa.
They were lifelong friends having studied together and then returning to Asia Minor, modern day Turkey, where their knowledge in the faith brought them to leadership roles in the Church as bishops, Basil of Caesarea and Gregory of Constantinople. Both men were leading figures in defending the traditional orthodox (the lower case “o” is intentional) teaching of the Church against the Arian heresy which had been condemned at Nicea in 325 AD but was still present throughout the Roman Empire.
A map showing Cappadocia and the locations of Caesarea and Nazianzus.
In recognition of their fidelity to the teaching of the Church and their influence on Church dogma and belief both Basil and Gregory have been given the title of Doctor of the Church.
Here are links to two short articles on Basil and Gregory.