Gregory of Nazianzus, 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.
A Byzantine-style icon depicting the Three Holy Hierarchs: (left to right:) Basil the Great, John Chrysostom and Gregory the Theologian.
Andrei Rublev, Gregory the Theologian (1408), Dormition Cathedral, Vladimir.
Basil of Caesarea, also called Saint Basil the Great, was a bishop of Caesarea Mazaca in Cappadocia, Asia Minor. He was an influential theologian who supported the Nicene Creed and opposed the heresies of the early Christian church, fighting against both Arianism and the followers of Apollinaris of Laodicea.
Russian icon of Basil of Caesarea
Icon of the Three Holy Hierarchs: Basil the Great (left), John Chrysostom (center) and Gregory the Theologian (right)—from Lipie, Historic Museum in Sanok, Poland.
Basil of Caesarea Correr Museum Venice