The Muslims then turned their attention to other routes: if France, and central Europe with it, could not be invaded over the Pyrenees, then perhaps from the south - from the Mediterranean. Indeed, Islam had already sent platoons ashore to attack towns on the island of Sardinia in 705 A.D., and attack the towns on Corsica in 713 A.D., but these were harassment raids, not full-scale invasions.
Islam stationed its occupational troops in parts of Corsica around 809 A.D., and the fighting on Sardinia was so violent that entire town were abandoned - some temporarily, like Caralis and Porto Torres; others permanently, like Tharros.
Between 823 and 827, the island of Crete was seized by seaborne Islamic forces; it had previously been the target of raiding parties. Setting up permanent military facilities, the Muslims used Crete as a naval base. From it, raiding parties were launched to plunder nearby coastlines, and pirate ships were launched to maraud among the cargo boats of the Mediterranean. Crete remained under the subjugation of Islamic armies until 961, when Byzantine forces aided the Cretans in rebelling against the oppressive invaders and regaining their independence and freedom.
The island of Malta met an even harsher fate. Looted and plundered by Muslims in 870 A.D., the destruction was so great that many of those not slaughtered outright in the invasion soon left to settle elsewhere, and Malta was almost deserted. A handful of Maltese remained under the small Islamic occupational force; taxed and forced into servitude, they lived under the restrictions of the Code of Umar (also sometimes cited as the 'Pact of Umar' or the 'Covenant of Umar'). In 1048/1049, larger numbers of Muslims began occupying the island; Malta was absorbing some of the overflow from the large Islamic armies stationed in Sicily. In 1091, Norman forces came to the aid of Malta and Sicily, helping them to expel the Muslim occupational troops; some Arabic-speaking bureaucrats remained in Malta as late as 1127.
The effective seaborne campaigns of the 700's and 800's emboldened the Muslims to try for bigger prizes. Perhaps, they reasoned, Islam could occupy central Europe after all. The goal - establishing a single caliphate or Islamic military government over Europe, Africa, and Asia - remained foremost in their minds, despite the fact that the chief obstacle to the formation of such a dominating dictatorship was not the resistance of the Europeans, who could be occasionally convincing, like Charles Martel, but who were often ineffectual. The chief obstacle was factional fighting within Islam; rival military leaders conducted battles against each other just as they conducted them against non-Muslims.
But the idea of exterminating Christians in Europe lured them onward, and if invasions over the Pyrenees seemed futile, then Europe had other points for attack. Historian Will Durant wrote that
fortified by mastery of the Mediterranean, the Saracens now looked appreciatively on the cities of southern Italy. As piracy was quite within the
Islamic military pattern of operation at this time, and as the operations based in Crete demonstrate, Muslim pirate ships raided
Christian shores to capture infidels for sale as slaves, Saracen fleets, mostly from Tunisia or Sicily, began in the ninth century to attack Italian ports. In 841, the Moslems took Bari, the main Byzantine base in southeastern Italy. A year later,
in 842, the Italian heartland would face ruin and destruction worse than anything it had ever seen before - not in Roman civil wars, not in the Punic wars. The Muslims unleashed savage destruction upon the Italians;
they swept across Italy and back, despoiling fields and monasteries as they went. In 846 eleven hundred Moslems landed at Ostia, marched up to the walls of Rome, freely plundered the suburbs and the churches of St. Peter and St. Paul, and leisurely returned to their ships. Seeing that no civil authority could organize Italian defense, Pope Leo IV took charge, bound Amalfi, Naples, Gaeta, and Rome in alliance, and had a chain stretched across the Tiber to halt any enemy. In 849 the Saracens made another attempt.
They tried, Durant writes, “to seize” Rome. The Italians had faced mass starvation after the Muslims had burned the crops in the fields. The misery was both physical and intellectual: the libraries burned by Islamic armies contained Roman and Greek works which were now lost forever. Despite the suffering inflicted upon them, the Italians were now both resolved and organized. When the Saracen fleet attempted to attack,
the united Italian fleet, blessed by the Pope, gave them battle, and routed them - a scene pictured by Raphael in the Stanze of the Vatican. In 866 the Emperor Louis II came down from Germany, and drove the marauding Moslems of south Italy back upon Bari and Taranto. By 884 they were expelled from the peninsula.
Although the Italian mainland was now free of the permanent presence of the Islamic occupational army, coastal raids continued - cities were plundered and sacked - for more than another century in Italy, France, and Mediterranean islands.