Capetian House of Anjou
In 1297, Pope Boniface VIII established on his own initiative ("motu proprio") a hypothetical "regnum Sardiniae et Corsicae" ("Kingdom of Sardinia and Corsica") in order to settle the War of the Sicilian Vespers diplomatically. This had broken out in 1282 between the Capetian House of Anjou and Aragon over the possession of Sicily. Despite the existence of the indigenous states, the Pope offered this newly created crown to James II of Aragon, promising him support should he wish to conquer Pisan Sardinia in exchange for Sicily.