Caliph Uthman granted Mu'awiya (governor of Syria) permission to mount a naval expedition against Byzantine-held Cyprus, a key step in creating an effective Muslim fleet in the eastern Mediterranean.
A Muslim fleet attacked Cyprus, briefly besieged Constantia, and secured a treaty obliging the island to pay tribute—establishing Cyprus as an early focal point of Arab–Byzantine naval contestation.
A follow-up expedition returned to Cyprus and installed a substantial garrison, strengthening Muslim leverage over the island and the sea lanes between Syria and Anatolia.
Muslim forces launched naval operations against Sicily during Uthman’s reign, demonstrating that early caliphal fleets could project power beyond the Levant into the central Mediterranean.
Off the Lycian coast near Phoenice/Finike, a Muslim fleet defeated Emperor Constans II’s navy in the Battle of the Masts, a landmark engagement in early Islamic sea warfare.
In preparation for attacks on the Byzantine capital, Umayyad fleets secured positions along the coasts of Asia Minor and used Cyzicus as an operational base to sustain campaigning in the Sea of Marmara.
The Umayyads initiated a major multi-year effort against Constantinople, using maritime mobility to maintain pressure on the city and its supply lines (though the exact chronology is debated in scholarship).
The siege ended in Byzantine success; Byzantine naval forces—associated in the sources with the use of Greek fire—destroyed attacking fleets and compelled the Umayyads to lift operations against Constantinople.
After earlier reversals, Umayyad forces retook Carthage in 698; the city’s destruction helped end Byzantine control in North Africa and shifted the strategic balance in the western Mediterranean.
Umayyad forces entered the Iberian Peninsula in 711, an operation dependent on maritime movement across the Strait of Gibraltar and tied to broader Umayyad Mediterranean strategy and raiding networks.
A massive Umayyad land-and-sea campaign under Maslama ibn Abd al-Malik commenced against Constantinople, aiming to cut off the city by both land and sea.
After a harsh winter, logistical strain, and effective Byzantine defense supported by allied Bulgarian forces, the Umayyads abandoned the siege—marking a decisive check on Umayyad maritime ambitions against the capital.
A Byzantine squadron defeated an Umayyad Egyptian fleet near Cyprus at Keramaia, illustrating continued high-stakes naval fighting in the eastern Mediterranean even late in the Umayyad period.
Umayyad Naval Expeditions and Mediterranean Raids (7th–8th centuries)
