Hierarch
Hierarch Callistus I Of Constantinople
патриарх Константинопольский 1350–1354, 1355–1363
Hierarch Callistus I, Patriarch of Constantinople (1350–1354, 1355–1363) — a disciple of St. Gregory Palamas and Venerable Gregory of Sinai, who spent 28 years as a monk on Mount Athos (Philotheou Monastery), the second Palamite patriarch of the See of Constantinople.
Hierarch Callistus I was a disciple of Venerable Gregory of Sinai and St. Gregory Palamas. For 28 years he was a monk at the Philotheou Monastery on Mount Athos. On June 10, 1350, he was elected Patriarch of Constantinople at the proposal of Emperor John VI Kantakouzenos, holding the see in 1350–1354 and 1355–1363, becoming the second Palamite patriarch after Isidore I. He firmly supported St. Gregory Palamas and his disciples in the Hesychast controversy. He composed lives of his teacher Venerable Gregory of Sinai and of St. Theodosius of Tarnovo. He died around 1363.