Kingdom of Sardinia
On 17 March 1861, law no. 4671 of the Sardinian Parliament proclaimed the Kingdom of Italy, so ratifying the annexations of all other Apennine states, plus Sicily, to the Kingdom of Sardinia. The institutions and laws of the Kingdom were quickly extended to all of Italy, abolishing the administrations of the other regions. Piedmont became the most dominant and wealthiest region in Italy and the capital of Piedmont, Turin, remained the Italian capital until 1865, when the capital was moved to Florence. But many revolts exploded throughout the peninsula, especially in southern Italy, and on the island of Sicily, because of the perceived unfair treatment of the south by the Piedmontese ruling class. The House of Savoy ruled Italy until 1946 when Italy was declared a republic by referendum. In this referendum the southern regions, including Sardinia, voted overwhelmingly in favor of the House of Savoy, with the results being 63.8% in favor of maintaining the monarchy.
Kingdom of Sardinia
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 restructured Europe after Napoleon's defeat, returned to Savoy its mainland possessions and augmented them with Liguria, taken from the Republic of Genoa. In 1847–48, in a "perfect fusion", the various Savoyard states were unified under one legal system, with the capital 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 first to Florence and then to Rome.