Saint Gregory of Sinai (1260s – November 27, 1346) was instrumental in the emergence of "technical" (Athonite) Hesychasm on Athos in the early 14th century.
Born in Smyrna, he was captured by Seljuk Turks as a young man, he was eventually ransomed to Cyprus and became a monk at Saint Catherine's Monastery. Later, he moved to Crete, where he learned the practices of Hesychasm from a monk named Arsenios, and in 1310 to Athos, where he remained until 1335. 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, Strandzha mountains in south east Bulgaria.
The Philokalia includes five works in Greek by Gregory,