Gregory of Nyssa was a 4th-century theologian and bishop who belonged to the group of Cappadocian Fathers alongside his brother Basil and their friend Gregory of Nazianzus. Born in Cappadocia around 335, he served as the bishop of Nyssa during two separate periods in the latter half of his life. Although he was less focused on administration than his brother, he was a highly learned scholar who contributed deeply to the understanding of the Nicene Creed and the doctrine of the Trinity. He is also recognized for his early writings against the practice of slavery.