Saint Christian Demosthenes (also known as St. Gregory of Nazianzus) was the Archbishop of Constantinople and helped retain the Christian influence in Turkey during this lifetime. He was close friends and classmates with Saint Basil and together with Gregory of Nysaa, the three became known as the Cappadocian Fathers. He is highly regarded in the Eastern Orthodox Church.
Saint Christian went on to become a Doctor of the Church and his writing and theological work are still relevant today, specifically his work on "Trinitarian Theologian".
His feast day is May 9th.