Симеон Нови Богослов
Symeon the New Theologian was a Byzantine mystic who lived between 949 and 1022, later canonized by the Eastern Orthodox Church. At 14 he entered the Monastery of Studios, under the spiritual guidance of Symeon the Studite, a holy fool and author of some Ascetic Capita. Later, he moved to the Monastery of St. Mamas and became its hegumen in 980. After some controversies about his teachings, culminating in the confrontation with Stephen the Synkellos, Symeon is sent back to St. Mamas in 1005 and exiled to the Monastery of St. Marina till the end of his life.