St Callistus, Patriarch of Constantinople (+c. 1363)

Saint Callistus, Patriarch of Constantinople, headed the Church of Constantinople in the reigns of the Emperors John Cantacuzene (1341–1355) and John Palaeologus (1341–1376). The holy father began his labours on Mount Athos. He was enthroned as patriarch in 1350, but after two years he laid down the heavy cross of the hierarch and, for the labour of silence, withdrew to the monastery of Saint Mamas on Tenedos, which he himself had founded. Afterwards the blessed Callistus returned to the see once more. The saint died around 1363 in Serbia, where John Palaeologus had sent him as an envoy. The hierarch Callistus is known for his spiritual writings.