John was a ninth-century monastic disciple of Saint Gregory the Decapolite, with whom he shared the ascetic life and the struggle against Iconoclasm. According to the synaxarion he was born toward the end of the eighth century and, while still young, became a disciple of Gregory, from whom he received monastic tonsure at a monastery in Thessalonica. Under the guidance of his teacher he is said to have attained great spiritual maturity. He is commemorated on April 11 and April 18.
John is principally remembered for his association with Gregory of Decapolis and Joseph the Hymnographer during the renewed Iconoclast persecution under the emperor Leo V the Armenian (813–820). The sources relate that Gregory, John, and Joseph went from Thessalonica to Constantinople to oppose the heresy, and that Gregory and John defended the veneration of the holy icons for several years in spite of persecution.
The accounts of John's later life diverge. The Slavic synaxarion (followed by the Orthodox Church in America) relates that John reposed soon after the death of his teacher Gregory, around the year 820, and that Joseph the Hymnographer afterward translated the relics of both Gregory and John, placing them in a church of Saint Nicholas the Wonderworker. A Greek tradition, by contrast, holds that after Gregory's death John traveled to Jerusalem, venerated the Holy Places, and settled in the Lavra of Saint Chariton in Palestine, where he continued his ascetic struggles and reposed in peace; in this tradition he is sometimes called John the Hesychast.
