St. Basil the Great, also known as Basil of Caesarea, (330 — 379 AD) was the bishop of Caesarea Mazaca in Cappadocia, Asia Minor. He, along with Gregory Nazianzen and Gregory of Nyssa, is commonly referred to as one of the Cappadocian Fathers.
During his life, Basil fought against numerous heresies, some of which are Eunomianism and Apollinarianism.
Basil is deemed as a saint by the Orthodox Church. May his prayers be with us all. Amen.
Letters to Amphilochius: