The ancient Greeks, notably Herodotus, called the island Kurnos; the name Corsica is Latin and was in use during the era of the Roman Republic. The Ionian Greeks had a brief foothold in Corsica with the foundation of Aleria in 566 BC. They were expelled by an alliance of the Etruscans and the Carthaginians. For a few centuries the Etruscans dominated the island but their alliance with the Carthaginians led them into opposition to the Roman Republic during the Punic Wars.
The island was under Etruscan and Carthaginian influence until 237 BC, when it was taken over by the Roman Republic. The Etruscans were confined to a few coastal settlements, such as Aleria and the Carthaginians were strong on neighboring Sardinia. The Romans, however, had a profound influence, colonizing the entire coast, permeating inland and changing the unknown indigenous language to Latin. Corsica remained under Roman rule until its conquest by the Vandals in AD 430. It was recovered by the eastern, or Byzantine Empire in 522, adding a late ancient Greek influence.
In the early decades of the fifth century, Roman authority all but vanished from Corsica. The island became disputed between the Ostrogoths, Roman foederati who were settled in the lands along the Riviera, and the Vandals, who were enemies of Rome and had established a kingdom in Tunisia. In 469, Gaiseric, the Vandal king, finally completed the subjugation of the isle. For the next 65 years the Vandals maintained their domination, the valuable Corsican forests supplying the wood for their pirate fleets.
After the Vandal state in Africa crumbled in the early sixth century under the onslaught of the Roman general Belisaurius, his lieutenant Cyril conquered Corsica in 534. The island was placed under the government of the Exarchate of Africa and was thus attached to what remained of the Eastern Roman Empire. However, the exarchate was not able to protect the island from the remaining barbarians: Ostrogoths and Lombards, who arrived in Italy in 568. Both peoples successively ravaged the isle and the entreaties of Pope Gregory I did nothing to spare it. Furthermore, the Byzantine governors were wont to extract burdensome taxes out of the population, to fund their battles elsewhere. With the fall of the exarchate in 698, Corsica was conquered by the Lombards under Liutprand (c. 725), posing as the protector of the Christian faithful from the depredations of the Saracens, who had begun to ravage the isle recently.
The first Muslim raid on Corsica took place in 713. These Muslims were Arabs from North Africa. After this, Byzantine authority wanned further and in 774, after conquering the Lombard Kingdom of Italy, the Frankish king Charlemagne proceeded to conquer Corsica for the Frankish hegemony, the Carolingian Empire, which he was establishing in western Europe.
In 806, however, occurred the first of a series of Moorish incursions from Spain. Several times defeated by Charlemagne's lieutenants, like Burchard, his constable, in 807, the Moors continually returned, and in 810 were decisively defeated (even exterminated) by an alliance of local powers and the Franks. They were crushed and exterminated by an expedition under Charles the Younger, but nonetheless continued their assaults. In 828, the defence of Corsica was entrusted to Boniface II of Tuscany, who conducted a successful expedition against the African Muslims and built the fortress later to bear his name (Bonifacio) in the south. For the next century, Corsica was a part of the March of Tuscany.
Boniface' son Adalbert I continued to war against the Muslims after 846; but, in spite of all efforts, they seem to have remained in possession of part of the island until about 930. During his conflicts with Otto I of Germany, Berengar II of Italy managed to make himself master of Corsica. In 962, Berengar was defeated and his son, Adalbert, fled to Corsica. He succeeded in holding the island against Otto and passing it on to his son, another Adalbert, who was defeated, however, by Otto II. Corsica was reattached to Tuscany, but Adalbert was allowed to hold as a fief.
Following Otto II's reestablishment of imperial authority over Corsica, a period of feudal anarchy began. The island at this time was generally divided, as it is down to the present time, into a north and a south. Throughout the island petty lords and more powerful regional potentates fought for supremacy and land. Among the lords of the south, the Counts of Cinarca soon gained preeminence. Soon after the year 1000, at a central location in the valley of Morosaglia, a sort of national diet or assembly was held with the intent of establish peace and rule of law over the whole island. The movement for peace was headed by Sambucuccio, lord of Alando. The movement succeeded in establishing order in the north, establishing the Terra di Comune, but the south — and the Cape Corso — remained as anarchic as ever.
The Terra was modelled along republican lines and was composed of autonomous communes. Each commune, or parish, elected a council of "fathers of the commune" who were in charge of the administration of justice under the direction of the podestà. Each podestà of an enfranchised district (or state) in turn elected a member to the supreme council, or magistracy, which was as it were the legislature of the Terra. The supreme council was called the Twelve because that was the number of enfranchised communes. Finally, as a check on their power and that of the podestà, the fathers of each commune elected a caporale charged with looking out for the interests of the poor and defenceless.
In 1012, in a final effort to subdue the wild barons of the south and the northern cape, the Terra called in William, Margrave of Massa. By 1020 he had succeeded in driving the count of Cinarca out of the island and enforcing peace, or at least reduced violence, on the southern barons. He allied with the communes and was able to hand Corsica on to his son, but his legacy was not one of unity and central government.
Towards the end of the eleventh century, the Papacy laid claim to Corsica, saying it had been donated to the Church by Charlemagne. All Charlemagne had really done was promise that stolen ecclesiastical lands would be returned. Nevertheless, the clergy of Corsica supported the Papacy and, in 1077, the Corsicans declared themselves subject to the Holy See in the presence of Landulf, Bishop of Pisa and Apostolic Legate to the island. Pope Gregory VII responded by making Landulf and his successors saecular lords and perennial apostolic legates of the isle. This was confirmed by Pope Urban II in 1190 and extended into a concession of full sovereignty.
Pisa replaced the papal legates who were governing the island with judges (judices) of their own appointment. Valuable chiefly as a source of timber for the Pisan fleet, but also as an important transit point for the slave trade, Corsica flourished under Pisan sovereignty, but crises soon arose. The Corsican episcopate resented Pisan overlordship and the rival Republic of Genoa schemed to have Rome reverse the grant of 1077. In 1138, Pope Innocent II divided the ecclesiastical rule of the island between Pisa and Genoa. However, the war between the two trading rival escalated and, in 1195, Genoa captured Bonifacio. The next twenty years were occupied by unrelenting Pisan efforts to recapture it. In 1217, the pope put an end to this by annexing the city to the Holy See.
During the 13th century, the feud between Pisa and Genoa introduced the struggle between Guelph and Ghibelline to Corsica also. In the course of the feud, the Terra di Comune invited Isnard Malaspina, a distant relative of William of Massa, to put a stop to the anarchy. A Count of Cinarca was reinstated and the war between Malaspina, Cinarca, Pisa, and Genoa dragged on with no side gaining the mastery until 1298, when Pope Boniface VIII formally bestowed the regnum Corsicae, Kingdom of Corsica, on James II of Aragon along with the regnum Sardiniae, Kingdom of Sardinia.
In 1325, James finally set out to conquer his dual island kingdom. Sardinia was attacked and the Pisans were destroyed. Unable to sustain themselves at sea, their fortunes in Corsica fell off abruptly. No comparable campaign, however, was launched at Corsica by the king. In 1347, after years of more feudal anarchy, a diet of caporali and barons offered the Genoese republic the sovereignty of the isle. By the agreement with Genoa, regular tribute was to be paid, but the Corsicans were allowed to retain their own laws and custome, to be governed by their own bodies, the Twelve in the north and a new council of Six in the south, and be represented at Genoa by an orator. It was, however, an inauspicious year. The Black Death arrived in Genoa in October and when it hit Corsica in the next months it decimated it, killing off perhaps two thirds of the population.