History of Sardinia
In the Early Middle Ages, through barbarian movements, the waning of the Byzantine Empire influence in the western Mediterranean and the Saracen raids, the island fell out of the sphere of influence of any higher government. This led to the birth of four kingdoms called "Judicates" (Latin: "Judicati"; Sardinian: "Judicados") in the 8th through 10th centuries. Falling under papal influence, Sardinia became the focus of the rivalry of Genoa and Pisa, the Judicates and the Crown of Aragon, which eventually subsumed the island as the Kingdom of Sardinia in 1324. The Kingdom was to last until 1718, when it was ceded to the Piedmontese House of Savoy; later, in 1861, it would thus become the Kingdom of Italy and finally in 1946 the Italian Republic.
Kingdom of Sardinia
The kingdom initially consisted of the islands of Corsica and Sardinia, sovereignty over both of which was claimed by the Papacy, which granted them as a fief, the "regnum Sardiniae et Corsicae" ("kingdom of Sardinia and Corsica"), to King James II of Aragon in 1297. Beginning in 1324, James and his successors conquered the island of Sardinia and established "de facto" their "de jure" authority. In 1420, after the Sardinian-Catalan War, the last competing claim to the island was bought out. After the union of the crowns of Aragon and Castile, Sardinia became a part of the burgeoning Spanish Empire. In 1720 it was ceded by the Habsburg and Bourbon claimants to the Spanish throne to Duke Victor Amadeus II of Savoy. The Kingdom of Sardinia came to be progressively identified with the states ruled by the main branch of the House of Savoy, which included, besides Savoy and Aosta, dynastic possessions since the 11th century, the Principality of Piedmont (a possession built up in the 13th century), and the County of Nice (a possession since 1388). While in theory the traditional capital of the island of Sardinia and seat of its viceroys was Cagliari, the Piedmontese city of Turin was the "de facto" capital of Savoy.