Leo III Launches Byzantine Iconoclasm
The emperor removes Christ's image from the palace gate and bans religious icons across the empire
Quick facts
- Emperor
- Leo III
- First phase
- 726 to 787 CE
- Decree against icons
- 730 CE
- Successor who intensified it
- Constantine V
What happened
Beginning around 726 CE, Emperor Leo III, having already saved Constantinople from Arab siege, turned against the veneration of religious images, ordering the removal of an icon of Christ that hung over the Chalke Gate, the ceremonial entrance to the Great Palace. Leo publicly opposed icon veneration in 726 CE and formally decreed in 730 CE that icons must be destroyed, a policy his successor Constantine V pursued even more aggressively, persecuting iconophiles with mutilation and execution and burning the Pelekete monastery. Pope Gregory III responded by declaring that anyone who destroyed icons would be excommunicated, deepening a rift between the eastern and western churches. Iconoclast theologians argued that any painted image of Christ improperly merged or separated his human and divine natures, a position that iconophile scholars like John of Damascus rejected by distinguishing veneration from worship.
Why it matters
Iconoclasm split the Byzantine church internally for over a century in two distinct phases and widened the theological and political gap between Constantinople and Rome that later contributed to the Great Schism of 1054. Many icons were destroyed permanently, though others survived by being smuggled to the empire's eastern provinces.
How we know
The World History Encyclopedia's article on Byzantine icons traces the controversy's two phases, 726 to 787 CE and 814 to 843 CE, quoting the historian T. E. Gregory's summary of the theological dispute, and Dumbarton Oaks's exhibition on Leo III's seals confirms his 730 CE decree and its origins at the Chalke Gate.
Sources
- World History Encyclopedia. Byzantine Icons · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- Dumbarton Oaks. Leo III (717-741) · Primary source (author-declared)doaks.org · Cited as a "primary" source (no stronger domain match).
See something wrong? . Corrections with a source get fixed fastest.
Part of a timelineThe Byzantine Empire27 events · How the eastern half of Rome outlived the west by a thousand years, then fell to Ottoman cannonView all →