Throughout the 13th century the struggle between Pisans and Genoese continued, reproducing in the island the feud of Ghibellines and Guelphs that was desolating Italy. In order to put a stop to the ruinous anarchy the chiefs of the Terra di Comune called in the marquis Isnard Malaspina; the Pisans set up the count of Cinarca once more; and the war between the marquis, the Pisans and Genoese dragged on with varying fortunes, neither succeeding in gaining the mastery. Then, in 1298, Pope Boniface VIII. added to the complication by investing King James of Aragon with the sovereignty of Corsica and of Sardinia. In 1325, after long delay, the Aragonese attacked and reduced Sardinia, with the result that the Pisans, their sea-power shattered, were unable to hold their own in Corsica. A fresh period of anarchy followed until, in 1347, a great assembly of _caporali_ and barons decided to offer the sovereignty of the island to Genoa. A regular tribute was to be paid to the republic; the Corsicans were to preserve their laws and customs, under the council of Twelve in the north and a council of Six in the south; Corsican interests were to be represented at Genoa by an _orator_.
The Genoese domination, which began under evil auspices--for the Black Death killed off some two-thirds of the population--was not destined to bring peace to the island. The feudal barons of the south and the hereditary _caporali_ of the north alike resisted the authority of the Genoese governors; and King Peter of Aragon took advantage of their feuds to reassert his claims. In 1372 Arrigo, count of La Rocca, with the assistance of Aragonese troops, made himself master of the island; but his very success stirred up against him the barons of Cape Corso, who once more appealed to Genoa. The republic, busied with other affairs, hit upon the luckless expedient of investing with the governorship of the island a sort of chartered company, consisting of five persons, known as the _Maona_. They attempted to restore order by taking Arrigo della Rocca into partnership, with disastrous results. In 1380 four of the "governors of the Maona" resigned their rights to the Genoese republic, and Leonello Lomellino was left as sole governor. It was he who, in 1383, built Bastia on the north coast, which became the bulwark of the Genoese power in the island. It was not till 1401, after the death of Count Arrigo, that the Genoese domination was temporarily re-established.