St John Damascene on Holy Images collects the three Apologetic Treatises against the Iconoclasts by John of Damascus (c. 675-749), the major Byzantine theologian and Doctor of the Church. The treatises are the central theological defense of the use of icons in Christian worship and were written during the first wave of the Byzantine Iconoclastic Controversy that began in 726 under Emperor Leo III.
The Iconoclastic Controversy was the major Byzantine theological and political conflict of the eighth and ninth centuries. Emperor Leo III and subsequent iconoclast emperors attempted to suppress the veneration of icons throughout the Byzantine Empire, with broad destruction of icons and persecution of iconophiles across the period. John of Damascus, writing from outside the empire in the Umayyad Caliphate where he was safe from imperial reach, produced the major theological defense of icon veneration that subsequent Orthodox theology built on.
The Seventh Ecumenical Council at Nicaea in 787 vindicated the iconophile position serious along the lines John had argued. The treatises remain central documents in Orthodox theology and continue to be studied by historians of Christian art and theology.