Gregory of Siani ( died 1346 )

Born in Smyrna, he was captured by Turks as a young man. He was eventually ransomed to Cyprus and became a monk at Saint Cathrine monastery on Mount Sinai. Later  he moved to Crete where he learned the practice of the Jesus prayer and hesychasm from the monk Arsenios. 

Eventuallyi n 1310 he moved to Hount Athos  to the Magoula skete near Phileotho Monestary  where he remained until 1335. Thus, having gained the experience of many centuries of the monastic life from the ancient monasteries, Gregory settled down in a solitary place for the purpose of pursuing "hesychia" (stillness doing the Jesus Prayer). 

With his contemporary Gregory of Palamas, he helped to establish Mount Athos as a center of hesychasm. From there he wrote and traveled widely teaching this approach to contemplation as a method of union with God.

Concerned with spreading of monasticism, Gregory founded several cells on Mount Athos, as well as four monasteries in Thrace.

Increasing Muslim raids on Athos pushed Gregory and some disciples into the Bulgarian empire, where he would find protection under Bulgarian Emperor Ivan Alexander and where he founded a monastery near Paroria, Strnadzah mountains in south east Bulgaria where he died on November 27th 1346.

 The Philokalia includes five works in Greek by Gregory,

• On Commandments and Doctrines, Warnings and Promises; on Thoughts, Passions and Virtues, and also on Stillness and Prayer: 137 Texts
• Further Texts
• On the Signs of Grace and Delusion, Written for the Confessor Longinos: Ten Texts
• On Stillness: Fifteen Texts
• On Prayer: Seven Texts