From the following Web site: http://www.metmuseum.org/toah/hd/icon/hd_icon.htm
With the following author's citation: Brooks, Sarah. "Icons and Iconoclasm in Byzantium". In Heilbrunn Timeline of Art History. New York: The Metropolitan Museum of Art, 2000-. http://www.metmuseum.org/toah/hd/icon/hd_icon.htm (originally published October 2001, last revised August 2009)
Definition of Iconoclasm
Iconoclasm literally means "image breaking" and refers to a recurring historical impulse to break or destroy images for religious or political reasons. For example, in ancient Egypt, the carved visages of some pharaohs were obliterated by their successors; during the French Revolution, images of kings were defaced.
In the Byzantine world, Iconoclasm refers to a theological debate involving both the Byzantine church and state. The controversy spanned roughly a century, during the years 726-87 and 815-43. In these decades, imperial legislation barred the production and use of figural images; simultaneously, the cross was promoted as the most acceptable decorative form for Byzantine churches. Archaeological evidence suggests that in certain regions of Byzantium, including Constantinople and Nicaea, existing icons were destroyed or plastered over. Very few early Byzantine icons survived the Iconoclastic period; notable exceptions are woven icons, painted icons preserved at the Monastery of Saint Catherine on Mount Sinai, Egypt, and the miniature icons found on Byzantine coins, including those of Justinian II (r. 685-95; 705-11).
Iconoclasm: The Source of Debate
The Iconoclastic debate centered on the appropriate use of icons in religious veneration, and the precise relationship between the sacred personage and his/her image. Fear that the viewer misdirected his/her veneration toward the image rather than to the holy person represented in the image lay at the heart of this controversy. Old Testament prohibitions against worshipping graven images (Exodus 20:4) provided one of the most important precedents for Byzantine Iconoclasm. The immediate causes for this crisis have been hotly contested by scholars. Among the many suggested causes are the rise of Islam and the emperor's desire to usurp religious authority and funds.
Icons after Iconoclasm
The Iconoclastic controversy had a profound effect on the production of Byzantine images after their reintroduction in 843. Changes shaped by the Iconoclastic debate included the evolution of distinct portrait types for individual saints; the development of more standardized programs of church wall decoration in mosaic and fresco; and the growing popularity of certain subjects such as Christ's Anastasis or the "Harrowing of Hell" (17.190.715a,b), and the Koimesis or the ...
Definition and explanation of the iconoclastic controversy, or how religious icons fell into disfavor.