In 717 AD, Constantinople, the capital of the Eastern Roman Empire (Byzantium), appeared doomed. In the preceding eighty years, Muslim Arabs had captured much of North Africa and the Middle East, and were poised to take Constantinople. To save Byzantium, the senate asked a Roman General, Leo III, to become Emperor. Leo and his brilliant son Constantine V radically altered the Byzantine imperial system militarily and culturally. Leo developed a novel idea - that God was angry with the Byzantine Christians because they worshiped Christian icons, relics, and pagan idols, thus ignoring the Second Commandment. God would favor the Byzantines only if they destroyed their icons and purified Christianity. Leo's policy set in motion a century-long conflict between the iconoclast (icon breaker) emperors and the iconophiles (icon lovers). This religious struggle culminated in a final battle to define Byzantine Christianity and the control of the Empire. This novel recounts who won, why and how.