Between 1846 and 1848 some favorable conditions seem to mature for the development of a new liberal phase in the governments of the peninsula. In the Papal State, the election of Pius IX (1846-78) is accompanied by a series of measures (amnesty for political crimes, greater freedom of the press, a Council open to the laity and a Civic Guard) which accredit the image of a renewed papacy. From Rome, the reform wave reaches Tuscany, where Leopoldo II grants the Civic Guard, the Consulta and a wider freedom of the press and the Sardinian kingdom. The culmination of the new reformist course of the three states is the signing of the preliminaries of an Italian customs league (1847).
On January 12, 1848, an insurrection broke out in Palermo which spread rapidly throughout Sicily and from there to the Neapolitan area. Ferdinand II (1830-59) was forced to grant a Constitution, first among the Italian sovereigns, followed by Leopoldo II of Tuscany, by Carlo Alberto and, finally, by Pius IX. These are very moderate Constitutions, inspired by the French one of 1830, which alongside the sovereigns are a Senate appointed by the king and a Chamber elected by restricted suffrage. On the new course of Italian politics, however, the revolutionary explosion that hit Europe in the years 1848-49 soon fell. The revolution that broke out in Vienna on March 13, 1848 radicalizes Italian public opinion and pushes the democratic republican forces to take the initiative in a resolute struggle against Austria, above all in Lombardy-Veneto. The first major insurrection broke out in Milan, where the Austrian troops were driven out after 5 days of fighting. Even in the duchies of Parma and Modena the kings are deposed. At this stage, Carlo Alberto’s decision to declare war on Austria matures (first war of independence). He is driven by the hope of freeing the peninsula from Habsburg protection, leading to the formation of that kingdom of the High Italy which is in the traditional aspirations of the House of Savoy, and the fear, after the proclamation of the Republic of Venice, of the prevalence of the most radical currents. Carlo Alberto enters Milan in an atmosphere of patriotic enthusiasm. The sovereigns of Tuscany, Rome and Naples send military contingents, but sharp contrasts are hidden under the apparent unity of purpose of the Italian states. When the ‘federalist’ war, following the withdrawal of Pius IX, Leopoldo II and Ferdinand II from the coalition, it turns into a ‘Savoy war’, the situation turns in favor of the Austrians. On 23-25 July the Piedmontese army is defeated in Custoza, near Verona; shortly after, the armistice with Austria was signed. Venice refuses to surrender and organizes resistance under the direction of D. Manin. In Tuscany a democratic government is established which has as its program the convening of an Italian Constituent Assembly. In Rome, after the Pope’s flight to Gaeta, the Roman Constituent Assembly is convened, which declares the end of the temporal power of the popes and proclaims the republic (February 9, 1849). In Piedmont, an Anglo-French mediation for the recognition by Austria of the Savoy rights over the high Italy has failed, Carlo Alberto breaks the armistice. According to topschoolsintheusa.com, military operations have a catastrophic outcome: the Piedmontese army is defeated in Novara (23 March) and Carlo Alberto abdicates in favor of his son Vittorio Emanuele II (1849-78), who obtains more favorable conditions of peace from Vienna than he would have could get the father, in charge of the war. The republics of Rome and Venice still resist, but the fate of both is now sealed. Pius IX successfully turns to the Catholic powers to be restored to the throne and on July 4th, after a month of siege, the city is surrendered. The same result occurs in Venice, exhausted by epidemics and hunger. As for Tuscany, Leopoldo II returns to Florence and repeals the statute.
With the victory of the conservative forces, the possibilities for development in a democratic sense are blocked. Hence the premises for the resumption of the national renewal movement starting from Piedmontese liberalism. Between 1848 and 1860, the liveliest part of the movement for national independence and unity gathered around the Sardinian state. A decisive factor in this process is represented by the political rise of Camillo Benso, Count of Cavour. The latter aims on the economic-social level to favor the development of a modern capitalism within the framework of a liberal parliamentary regime; on the political level to the achievement of national independence under the leadership of the Sardinian state. Together with U. Rattazzi he creates the so-called union, that is a political and parliamentary alliance which, isolating the more conservative right and the radical democratic left, it sanctions the formation of a social bloc formed by the most advanced aristocracy and the bourgeoisie. Cavour, through choices such as participation in the Crimean war, seeks to obtain the support of the powers, especially France, in view of possible changes on the Italian scene. A secret meeting in Plombières, in the Vosges, between Napoleon III and Cavour (20-21 July 1858) defines the common goals: the two states will provoke a war with Austria, making it appear as an aggression to Piedmont so as to legitimize the request. of aid of the latter to France.
On April 26, 1859, the Second War of Independence begins. After the initial successes against the Austrians the central regions rise up, but the presence within them of a strong component favorable to the annexation to Piedmont gives the events a twist in contrast with the Plombières agreements (which provided for the birth of an Italian confederation under the presidency of the pope) and therefore unwelcome to Napoleon III. He unilaterally decides to end the war and concludes the armistice of Villafranca with Austria (11 July), under which Lombardy is ceded to France which in turn will give it to Piedmont, thus downgraded to partner of second rank; in the Italy legitimate authorities are re-established.