Saint Cyril
Because of his popularity in Upper Egypt and his zeal for Orthodoxy, Shenoute was chosen by Saint Cyril the Great to accompany him in representing the Church of Alexandria at the Ecumenical Council of Ephesus in 431 AD. There he provided the moral support that Saint Cyril needed to defeat the heresy of Nestorius, Bishop of Constantinople. The eventual exile of the latter to Akhmim, Shenoute's backyard, was a testimony to the impression that Shenoute had made upon the attendees of this council.