Arab siege of Constantinople repelled by Leo III
- Date
- 717–718 CE
- Category
- Military & conflict
- Region
- Byzantium (Constantinople)
- Era
- Post-Classical / Medieval
- Significance
From the summer of 717 the Umayyad Caliphate mounted its greatest assault on Constantinople, sending a large army under Maslama across Anatolia and an enormous fleet into the Sea of Marmara to take the Byzantine capital and open the road into Europe.
The newly enthroned emperor Leo III the Isaurian relied on the formidable Theodosian land walls, the city's stockpiled supplies, and naval Greek fire, which devastated the Arab galleys. A bitterly cold winter, famine and disease wore down the besiegers, a Bulgar attack inflicted heavy losses on the land army, and reinforcing fleets were destroyed. After about a year the Umayyads abandoned the siege in 718, and storms wrecked most of their retreating fleet. The failure ended the era of all-out Umayyad attempts to conquer the Byzantine heartland, preserved Constantinople and the empire as a bulwark on the southeastern frontier of Christendom, and is frequently cited alongside Tours as one of the checks that halted early Islamic expansion into Europe.
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Empires active in 717–718 CE
- Umayyad Caliphate661 CE – 750 CE
- Tang Dynasty618 CE – 907 CE
- Byzantine Empire330 CE – 1453 CE
- Kanem-Bornu Empire700 CE – 1900 CE
- Tibetan Empire618 CE – 842 CE
- Khazar Khaganate650 CE – 969 CE
Related military & conflict events
- The An Lushan Rebellion devastates Tang China755–763 CE
- Battle of the Yarmuk ends Byzantine rule in SyriaAugust 636 CE
- Umayyad conquest of Hispania begins at Guadalete711 CE
- Battle of Tours halts Umayyad expansion into FranciaOctober 732 CE
- Battle of Talas halts Tang expansion and seeds papermaking in the Islamic worldJuly 751 CE
- Arab conquest of Egypt and founding of Fustat641–642 CE
Further reading
The wider story
The Great Arab Conquests
Leading historian's narrative of the early Islamic conquests.
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