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.
Papal States under Pope Pius IX
After the Second Italian War of Independence, much of northern Italy was unified under the House of Savoy's government; in the aftermath, Garibaldi's expedition of the Thousand overthrew the Bourbon monarchy in the Kingdom of the Two Sicilies. Afraid that Garibaldi would set up a republican government in the south, the Sardinians petitioned Napoleon for permission to send troops through the Papal States to gain control of the Two Sicilies, which was granted on the condition that Rome was left undisturbed. In 1860, with much of the region already in rebellion against Papal rule, Sardinia conquered the eastern two-thirds of the Papal States and cemented its hold on the south. Bologna, Ferrara, Umbria, the Marches, Benevento and Pontecorvo were all formally annexed by November of the same year, and a unified Kingdom of Italy was declared. The Papal States were reduced to the Latium region surrounding Rome, raising the Roman Question.