Kingdom of Sardinia 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. When the mainland domains of the House of Savoy were occupied and eventually annexed by Napoleonic France, the king of Sardinia made his permanent residence on the island for the first time in its history. The Congress of Vienna (1814–15), which
Kingdom of Sardinia 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