Siege of Constantinople (674–678)

An Umayyad naval campaign against Constantinople, traditionally dated 674–678, that failed to capture the Byzantine capital.

Greek fire: An incendiary weapon used by the Byzantine Empire, especially in naval warfare. Byzantine sources associate its use against Arab fleets with the defense of Constantinople.
Muawiya I: The first Umayyad caliph, who ruled from 661 to 680. He directed the caliphate during the campaign against Constantinople.
Constantine IV: Byzantine emperor from 668 to 685 who defended Constantinople against the Umayyads. His reign encompassed the defense and the diplomatic aftermath of the campaign.
Byzantine–Umayyad truce of 678: A reported settlement ending the conflict between the Byzantine Empire and the Umayyad Caliphate around 678. Later accounts connect the campaign’s failure with a truce and tribute arrangements.
Theodosian Walls: The massive land walls that protected Constantinople from siege. The city’s land defenses made a direct assault difficult even as the fleet blockaded it.
Early Muslim conquests: The rapid expansion of Muslim-ruled states across the Middle East, North Africa, and beyond in the seventh century. The campaign followed the conquests that brought Byzantine territories under Arab rule.
Theophanes the Confessor: A Byzantine monk and chronicler whose history covers events from the late third to the early ninth century. His account is a major source for the traditional chronology of the siege.
Second Arab siege of Constantinople: The Umayyad siege of Constantinople in 717–718, defeated by Byzantine defenses and winter hardship. This later siege was a separate campaign, despite similar goals and overlapping traditions.
Golden Horn: A natural harbor along Constantinople’s northern side, sheltered by a chain at its entrance. Control of this harbor helped protect the city’s maritime approach.
Umayyad Caliphate: The Islamic caliphate ruled by the Umayyad dynasty from 661 to 750. The caliphate supplied the forces and political direction for the attack.

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