Saint Cosmas, Bishop of Chalcedon, and his companion Saint Auxentius, lived during the ninth century, at a time when the Iconoclasts oppressed the Orthodox. Saint Cosmas while still in his youth had entered a monastery and received monastic tonsure. Later, he was consecrated as Bishop of Chalcedon, and zealously defended the Orthodox Faith against the Iconoclast heretics. Saint Auxentius helped the saint in this struggle.
The Iconoclasts tried in many ways to win the saint over to their side, but he remained faithful to Orthodoxy until the very end. Saint Cosmas did not obey the decree of Emperor Leo the Armenian (813-820) ordering the removal of the holy icons from the churches. For this he was expelled from his See and exiled to prison.
When the saint returned from exile, he and Saint Auxentius continued to defend the veneration of holy icons. At the mitigation of the persecution, Saint Cosmas was weak in body, but remained strong in spirit. Saint Cosmas and Saint Auxentius steadfastly preserved the Orthodox Faith until the end of their lives.