The town of Aleria was subject to repeated raids by Arab fleets in the eighth and ninth centuries, and, eventually, abandoned.
The diocese was suppressed by the Civil Constitution of the Clergy in 1790, and was not revived by the Concordat of 1801 between the French Consulate and the Papacy.
The bishop and cathedral retreated to the hillside town of Cervione, above the beach of Campoloro, some 25 km north of Aleria.
In 846, Adelbert the tutor Corsicanae insulae informed Pope Sergius II that a force of 11,000 Saracens, with 73 ships and 500 cavalry, had come.
[12] On 29 November 1801, in accordance with the Napoleontic Concordat of 1801, it was suppressed as the territory of the diocese of Ajaccio was extended to the whole of Corsica.