The Kingdom of Sardinia was a state in Europe from the early 14th century until the mid-19th. It 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 fact their de jure authority. In 1420 the last competing claim to the island was bought out. After the union of the crown of Aragon with that of 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 the Duke Victor Amadeus II of Savoy. The kingdom of Sardinia came progressively to be identified with the entire domain ruled by the House of Savoy, which included, besides Savoy and Aosta, dynastic possessions since the 11th century, the Piedmont (a possession built up in the 13th century) and Nice (a possession since 1388). While the traditional capital of Sardinia and seat of its viceroys was Cagliari, the Piedmontese city of Turin was the de facto capital of the House of Savoy.
When the mainland domains of the House of Savoy were occupied and eventually annexed by the 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 restructured Europe in light of Napoleon's defeat, returned to Savoy its mainland possessions and augmented them with Liguria, taken from France. In 1847–48, in a "perfect fusion", the various Savoyard states were unified under one legal system, with its captial in Turin, and granted a constitution, the Statuto Albertino. There followed the annexation of Lombardy (1859), the central Italian states and the Two Sicilies (1860), Venetia (1866) and the Papal States (1870). On 17 March 1861, to more accurately reflect its new geographic extent, the Kingdom of Sardinia changed its name to the Kingdom of Italy, and its capital was eventually moved to Rome.