Saint Peter of Atroa (c. 773–837) is among the better-documented Byzantine monastic saints of the iconoclast period, his life recorded by his disciple and successor Saint Sabas in the Life of Saint Peter of Atroa. He was born around 773 in Asia Minor, most likely near Mount Olympus in Bithynia, and lived through one of the most turbulent theological conflicts in Byzantine history — the controversy over the holy icons.
Little reliable detail survives of his parents or childhood; the hagiography describes an early inclination to asceticism and an entry into monastic life while still young. He became a disciple of the ascetic Saint Paul of Atroa, founder of the monastic community at Mount Atroa in Bithynia, and under his guidance embraced a life of strict fasting, prayer, obedience, and labor. After Paul's repose, Peter emerged as a leading monk of the community and in time its abbot, with charge of monks spread among several dependent houses and hermitages.
His mature years fell within the second period of Byzantine iconoclasm (815–843), revived under the emperor Leo V. Peter openly upheld the veneration of icons and kept communion with the iconophile monastic movement, which drew the suspicion of the imperial authorities; he endured surveillance, harassment, and seasons of forced displacement, yet held to the Orthodox confession. The Life records extensive travels through Asia Minor, visiting monasteries, encouraging monks, organizing communities, and keeping contact with the leaders of the Church.
By the end of his life he oversaw a substantial monastic network reaching well beyond the original house at Atroa. He reposed in peace in 837, only a few years before the final restoration of the icons under the empress Theodora in 843, and was venerated almost at once within Byzantine monastic circles.