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.
France–Italy relations
The border between France and Savoy had remained in flux since the Italian Wars. In the early modern period, it was fixed in the Treaty of Turin of 1696. After the War of the Spanish Succession, the House of Savoy made large territorial gains, becoming the 18th-century nucleus for the later Italian unification. Savoy was occupied by revolutionary France from 1792 to 1815. Savoy, along with Piedmont and Nice, was conjoined into the Kingdom of Sardinia at the Congress of Vienna in 1815, In 1860, under the terms of the Treaty of Turin, Savoie and Nice was annexed by France, while Lombardy passed to Italy. The last Duke of Savoy, Victor Emmanuel II, became King of Italy.