The Byzantine Iconoclasm encompasses two periods in the history of the Byzantine Empire when religious images of icons came under scrutiny by religious and imperial authorities within the Orthodox Church and the temporal imperial hierarchy. The First Iconoclasm, as it is sometimes called, lasted between about 730-787. The Second Iconoclasm was between 814-842 .
According to the traditional view, Byzantine Iconoclasm constituted a ban on religious images by Emperor Leo III and continued under his successors, and was accompanied by widespread destruction of images and persecution of supporters of the veneration of images.
Iconoclasm, Greek for "image-breaking," is the deliberate destruction within a culture of the culture's own religious icons and other symbols or monuments, usually for religious or political motives. Conversely, people who revere or venerate religious images are derisively called "iconolaters. "
Iconoclasm has generally been motivated theologically by an Old Covenant interpretation of the Ten Commandments, which forbade the making and worshiping of "graven images. " The two periods of iconoclasm in the Byzantine Empire during the 8th and 9th centuries made use of this theological theme in discussions over the propriety of images of holy figures, including Christ, the Virgin and saints. It was a debate triggered by changes in Orthodox worship, which were themselves generated by the major social and political upheavals of the seventh century for the Byzantine Empire .
Traditional explanations for Byzantine iconoclasm have sometimes focused on the importance of Islamic prohibitions against images influencing Byzantine thought. According to Arnold J. Toynbee, for example, it was the prestige of Islamic military successes in the 7–8th centuries that motivated Byzantine Christians to adopt the Islamic position of rejecting and destroying idolatricous images. The role of women and monks in supporting the veneration of images has also been asserted.
Social and class-based arguments have been put forward, such as that iconoclasm created political and economic divisions in Byzantine society; that it was generally supported by the Eastern, poorer, non-Greek peoples of the Empire who had to constantly deal with Arab raids. On the other hand, the wealthier Greeks of Constantinople and also the peoples of the Balkan and Italian provinces strongly opposed Iconoclasm. In recent decades in Greece, Iconoclasm has become a favorite topic of progressive and Marxist historians and social scientists, who consider it a form of medieval class struggle and have drawn inspiration from it.