Saint Nil Sorsky (born c. 1433—died 1508; feast day May 7) was the first Russian mystic to write about the contemplative life and to formulate a guide for spiritual self-perfection.
After a trip to Constantinople and Mount Athos, he founded his own monastery beside the Sora River (whence the name Sorsky). At a council in Moscow (1503), Nil spoke against monastic ownership of property and thus came to be identified with the “nonpossessor” party within the Russian Church. He was also opposed to the involvement of monks in social-welfare and political activity. The writings and monastic rule of this Russian saint influenced Russian monasticism for several centuries.