Caesarius of Nazianzus was a 4th-century physician and political official who served at the Byzantine court. Born in Arianzos to the bishop Gregory the Elder, he was the younger brother of the theologian Gregory of Nazianzus. Although he achieved great success in medicine and later held the position of quaestor of Bithynia, he remained a committed Christian, even resisting the influence of Emperor Julian. He died in 368 following a plague that struck shortly after an earthquake in Nicaea.