Iconoclasm: Literally, “destruction of images.” Historically, iconoclasm arose in the eighth century as the practice of destroying images (icons) of Jesus Christ often found in the gathering places of certain Christian churches. Many Christians worshiped the icons as representations of Jesus Christ in his physical incarnation. The iconoclastic controversy began in A.D. 725 when Emperor Leo III decided to have icons destroyed because he thought icon worship was idolatrous and a hindrance to the conversion of Jews and Muslims.
Stanley J. Grenz;David Guretzki;Cherith Fee Nordling. Pocket Dictionary of Theological Terms (Kindle Locations 677-680). Kindle Edition.