Saint Kallistos II, Patriarch of Constantinople
Saint Kallistos (Kállistos) lived a life of asceticism at the Magul Skete on Mount Athos (opposite Philotheou Monastery), abiding there for twenty-eight years. He was a disciple of Saint Gregory of Sinai (August 8), whose Life he wrote.
He became closely acquainted with Saint Ignatius Xanthopoulos, who was born in Constantinople. They have been described as two bodies united with one soul, in a spiritual sense, for both were godly-minded and attained great heights of noetic prayer. According to Saint Symeon of Thessaloniki (September 15), Kállistos and Ignatius Xanthopoulos beheld the Uncreated Light, just as the Apostles had on Mount Tabor, and their faces seemed to “shine like the sun.” Together they wrote the "Directions to Hesychasts in One Hundred Chapters," a treatise in 100 sections on the ascetical practices of the Hesychast monks. This was incorporated into the Philokalia of the Wakeful Fathers by Saint Nikodemos the Hagiorite, and it had a profound influence on Orthodox spirituality.
In 1397 Saint Kállistos was elevated to the patriarchal throne, but for only three months during the reign of Manuel Paleologos (1391-1425). He agreed to travel to Serbia in order to bring peace to that church, stopping along the way at Mount Athos. There Saint Maximos Kavsokalyvites (January 13) predicted: "This Elder shall not see his flock again, for the funeral dirge, "Blessed are the blameless in the way" (Psalm 118/119:1) is sounding behind him.
When he reached Serbia, Saint Kállistos exchanged this temporal life for everlasting life.