When he was still as yet only governor of Syria, the first of the Umayyad caliphs, Mu'āwiyyah, launched the initial Muslim challenge to Byzantine maritime domination of the Mediterranean with a raid on Cyprus in AD 649, just seventeen years after the death of Muhammad. Soon afterwards, in 655, the Muslims won their first great naval victory over the Byzantines off Phoenix, near Chelidonia in Lycia. From then on Islam was to challenge Christendom at sea in the Mediterranean for a thousand years. In the early Middle Ages, pace the great naval assaults on Constantinople itself in 673-9 and 717 18, the most serious threat from Islam developed in the ninth and tenth centuries. During that period Muslims were able in some cases to capture and hold, and in other cases to compromise seriously Christian authority over, all of the islands and some of the important mainland regions and bases along the trunk routes of the sea. Cyprus saw a shared condominium of power between the Abbasid Caliphate and Byzantium (figure 26). Muslim fleets, ghazi squadrons, and corsair ships operated from Umayyad Spain, Aghlabid Tunisia, the Balearics, Sicily, Bari, Taranto, Monte Garigliano, Fraxinetum, Crete, Tarsus and Tripoli in Syria, and to some degree from Corsica, Sardinia, Rhodes, and Cyprus. Their operations took the form of corsair cruises by single ships or small flotillas, raids on coasts and islands for booty and slaves by ghazi squadrons pursuing the ghazw of jihād, and full-scale invasions by large fleets.