AD 535 - 827 - The Eastern Roman empire conquered Sicily, and much of the Mediterranean coastline, in the sixth century, ruling its Italian holdings from Ravenna. But the empire's control of Italy was never complete, and it had to face continual attacks from the Lombards who had become dominant in the north and much of central Italy. The remaining Eastern Roman influence in the south was gradually whittled away after the sudden rise of the Islamic empire, although it took until 827 for the Muslims to seize control of Sicily. Details about the Roman administration of the island seem to be scanty, as they are with all their Western Mediterranean holdings, with not even a list of local governors being available.
AD 535 - Sicily is recaptured for the empire by the Eastern Roman empire during the campaigns of General Belisarius which ultimately result in the creation of the exarchate of Ravenna in mainland Italy.
AD 638 - In response to the rebellion of John of Conza, the exarchate of Ravenna creates the duchy of Naples, the sixth such division of Eastern Roman territories in Italy. A dux or duke is brought into Italy to command Naples, and he reports directly to the strategies of Sicily. The new duchy is similar in size and territory to the modern province of Naples.
AD 652 - The island undergoes its first invasion by the Islamic empire. The forces of Caliph Uthman attack the Eastern Roman defences but soon withdraw. This is probably due to a weak supply chain, but it may also be due to advancing Roman forces from Ravenna. Frustrated by his attempts to remove Pope Martin from office under the orders of Emperor Constans II, Exarch Olympus switches his allegiance. Now supporting the pope, he declares himself emperor. In the same year he marches into Sicily, although who he is about to fight, the Roman strategies or the Arabs, is not clear. Instead, he is struck down by disease and dies.
AD 661 - Eastern Roman Emperor Constans II is highly interested in affairs in southern Italy, which causes him to move his capital to Syracuse on Sicily. He appoints a native of Naples, one Basil, as the new dux, the military commander of the city. This is not the first dux to be appointed, but it seems to be the first about whom anything concrete is known, the previous incumbents being foreigners who had been forced to answer directly to the strategies of Sicily. Now Naples is its own master.
AD 695 - The Islamic Wali of Ifriqiyya and the Maghreb, Hasan ibn al-Nu'man, captures Carthage in 695 and the Eastern Roman administration retreats, possibly to Caralis on Sardinia. This gives the Arabs a firm base from which to launch more sustained attacks on Sicily. The island of Pantelleria, located midway between Sicily and modern Tunisia, is captured by Arabs, but internal discord prevents an attack on Sicily from being organised. Much of the eighth century is characterised by Arab naval attacks on Roman fleets in the Mediterranean, all of which keep Sicily safe.
AD 740 - Ubeidallah ibn al-Habhab al-Maousili, the Islamic Wali of Ifriqiyya and the Maghreb launches an invasion of Sicily which results in him seizing Syracuse. He readies his forces to take the rest of the island, but a Berber revolt in Ifriqiyya forces him to abandon the idea.
AD 755 - 756 - The exarchate of Ravenna is briefly re-captured by the resurgent Lombards, but the following year the Carolingian Franks recapture the territory. The ex-Byzantine exarchate is handed back to Rome as the Papal States and northern Italy becomes part of the Carolingian empire. Sicily as a Byzantine possession is now more isolated.
AD 826 - Euphemius, commander of the Byzantine fleet of Sicily, forces a nun to marry him. Emperor Michael II orders General Constantine to seize Euphemius and remove his nose in punishment. Given no choice, Euphemius revolts, killing Constantine and occupying Syracuse in the process. Subsequently he is driven off the island and takes refuge with Ziyadat Allah I in Tunis. He offers Sicily to the emir in exchange for safety and a position as a general. Once again the Byzantine empire was betrayed by one of its own commanders, Euphemius, mirroring its loss of Carthage in 695, and Sicily was similarly lost.
AD 827 - 828 - Ziyadat Allah promises to put Euphemius in command of Sicily in return for annual tribute. He sends an invasion force that is aided by Euphemius' own fleet. The Aghlabids win the first battle and lay siege to Syracuse for a year. A large Byzantine force sent from Palermo which is assisted by a fleet from Venice under the personal command of the doge, Giustiniano Participation, is defeated. Sicily is in the hands of the Arabs as part of the Islamic empire. This loss virtually ends Roman domination of the Western Mediterranean.