Gregory of Gornjak, also known as Gregory the Younger and Gregory the Silent, was a Serbian hesychast monk of the second half of the fourteenth century who founded the monastery of Gornjak in Moravian Serbia. He is numbered among the Sinaites, the company of monastics whose spiritual descent traced back to Mount Sinai and who carried the practice of inner prayer through the Balkans during this period. He is commemorated on December 7, the day after the feast of Saint Nicholas; the Serbian Church observes him on December 20 (December 7 by the old calendar reckoning).
By tradition Gregory was formed in the Sinaitic and hesychast schools of his age. Sources record that he spent time in the monastic settlement of Paroria in Thrace under Ilarion, himself a former disciple of Gregory of Sinai, and that he studied at Mount Sinai in the lineage of Gregory of Sinai and of Romylos of Vidin. With a company of Serbian, Bulgarian, and Greek monks he returned to Moravian Serbia between 1375 and 1379, part of the wider movement of hesychasts who, after the Battle of Maritsa in 1371, sought refuge in the Serbian lands under Prince Lazar.
Prince Lazar built the monastery of Gornjak for Gregory's community and endowed it to him and his brethren by a written charter, which was confirmed by the Serbian patriarch on May 17, 1379. The monastery lies in the gorge of the Mlava river, between Žagubica and Petrovac na Mlavi, and its church is dedicated to the Entrance of the Theotokos into the Temple. Gregory spent the remainder of his life there and was buried within it. In the sixteenth and seventeenth centuries his relics were removed for safekeeping to the monastery of Oreškovica before being returned to Gornjak.