Stephen was a Constantinople monk who became hegumen of Mount St. Auxentius across the Bosphorus from the capital, governing a great Greek monastery during the iconoclast persecutions of Emperors Leo III and Constantine V. In 754 he refused to sign the iconoclast decrees of the Council of Hieria; in 763 he refused again at a public confrontation with Constantine V at the Daphne Palace.
By the emperor's order Stephen and many of his monks were brutally tortured and exiled. Brought back to Constantinople for re-examination in 764, he was lynched in the streets by a mob whipped up against him — a martyrdom unique in early medieval Christianity in being inflicted at imperial behest by ordinary citizens.
He is the principal early martyr of the iconoclast persecutions, honored on November 28 by the Byzantine Church together with the great wave of monks martyred for the icons. His Life by Stephen the Deacon is one of the great hagiographic texts of 9th-century Byzantium and a primary source for the iconoclast era.