PATRISTICS/ John Cassian
Saint John Cassian (c. 360 - 435), John the Ascetic, or John Cassian the Roman, was a Christian monk and theologian celebrated in both the Western (Feast Day July 23) and Eastern Churches (Feast Day July 29) for his mystical writings.
John Cassian was born around 360, most likely in the region of Scythia Minor (now Dobruja in modern-day Romania and Bulgaria), although some scholars assume a Gallic origin.
As a young adult he and an older friend, Germanus, traveled to Palestine, where they entered a hermitage near Bethlehem. After remaining in that community for about three years, they journeyed to the desert of Scete in Egypt, which was rent by Christian struggles. There they visited a number of monastic foundations.
Approximately fifteen years later, about 399, Cassian and Germanus fled the Anthropomorphic controversy provoked by Theophilus, Archbishop of Alexandria, with about 300 other Origenist monks. Cassian and Germanus went to Constantinople, where they appealed to the Patriarch of Constantinople, Saint John Chrysostom, for protection. Cassian was ordained a deacon and was made a member of the clergy attached to the Patriarch while the struggles with the imperial family ensued. When the Patriarch was forced into exile from Constantinople in 404, the Latin-speaking Cassian was sent to Rome to plead his cause before Pope Innocent I.
While he was in Rome, Cassian accepted the invitation to found an Egyptian-style monastery in southern Gaul, near Marseilles. He may also have spent time as a priest in Antioch between 404 and 415. In any case, he arrived in Marseilles around 415. His foundation, the Abbey of St Victor, was a complex of monasteries for both men and women, one of the first such institutes in the West, and served as a model for later monastic development.
Cassian's achievements and writings influenced St Benedict, who incorporated many of the principles into his monastic rule, and recommended to his own monks that they read the works of Cassian. Since Benedict's rule is still followed by Benedictine, Cistercian, and Trappist monks, John Cassian's thought still exercises influence over the spiritual lives of thousands of men and women in the Latin Church. (taken from Wikipedia and Orthodox Wikapedia)