Basil of Caesarea
Gregory the Theologian (also known as Gregory of Nazianzus) is one of the Three Hierarchs (Ancient Greek: Οἱ Τρεῖς Ἱεράρχαι; Greek: Οι Τρεις Ιεράρχες). The other two are Basil the Great, also known as Basil of Caesarea and John Chrysostom.