A young and competent medical physician, Caesarius was the younger brother of Gregory of Nazianzus, and served various emperors in Constantinople, including Julian the Apostate. Unlike his religous brother, Caesarius was more comfortable with life at court and the politics of empire, although he remained vigilant against the loss of his Christian faith. He was nominated Quaestor for Bithnya, an extremely wealthy position. Narrowly avoiding the Nicean earthquake, he was struck by the ensuing plague and died shortly after receiving Baptism.