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.
Italian Social Republic
In July 1943, after the Allies had pushed Italy out of North Africa and subsequently invaded Sicily, the Grand Fascist Council—with the support of King Victor Emmanuel III—overthrew and arrested Mussolini. The new government began secret peace negotiations with the Allied powers. When the Armistice of Cassibile was announced 8 September, Germany was prepared and quickly intervened. Germany seized control of the northern half of Italy, freed Mussolini and brought him to the German-occupied area to establish a satellite regime. The Italian Social Republic was proclaimed on 23 September 1943. Although the RSI claimed most of the lands of Italy as rightfully belonging to it, it held political control over a vastly reduced portion of Italy. The RSI received diplomatic recognition from only Germany, Japan and their puppet states.