At the end of the 18th century the peninsula that from 1860 would be called the Kingdom of Italy was fragmented into many autonomous regions and city states. The northern regions were under Habsburg rule, the central part consisted of the Papal States, and the southern Kingdom of Naples was ruled by the Bourbons. After the Napoleonic invasion of 1796, political conditions changed rapidly. The Napoleonic Kingdom of Italy was proclaimed in the former Habsburg territories in 1805, Rome annexed in 1808, and Naples ruled by a French general. The defeat of 1813 restored the status quo ante, with the Habsburg Empire annexing Lombardy, Veneto, Istria, and Dalmatia. This restoration, and the reactionary policies of the restored regimes, provoked popular discontent, resulting in popular uprisings that marked the beginning of the Italian unification process, the Risorgimento. (The term refers to the political process of creating a united nation-state as well as to the struggle for resurrection (risveglio) of the spirit of the Italian people.)

Several secret societies worked towards an independent and united Italy, the most important being the Carbonari (“charcoal makers”). This network of revolutionaries, inspired by Freemasonry and the French Revolution, strongly opposed the conservative political changes and aimed at creating a constitutional republic. They initiated the southern revolutions of 1820-21 and demanded liberal reforms. They succeeded to the extent that King Ferdinand I of the Kingdom of the Two Sicilies signed a liberal constitution based on the model of the Spanish constitution of 1812. Alarmed by the progress of the Carbonari, the Holy Alliance and the newly appointed king of Sardinia Charles Felix sent their armies and defeated the southern insurgents. In 1831 the Carbonari members staged a revolution in Modena and in several cities in the Papal States.

After being defeated by the Habsburg army, the Carbonari practically ceased to exist. In 1831 a former member of the Carbonari, Giuseppe Mazzini (1805–1872), founded a new association, Giovine Italia (“Young Italy”). Contrary to the Carbonari, Giovine Italia enunciated a clear programme stating its aim to unify Italy, and spread this through propaganda and education. Mazzini’s movement failed, however, to mobilize the biggest social group on the Italian peninsula, the peasants, since, fixated as he was on national unification, Mazzini neglected the importance of social reforms for the peasantry.

More moderate movements for constitutional reform appeared as well, such as the neoguelfi and the neoghibellini (who took their names from the medieval factions in the power struggle between Pope and Emperor). The neoguelfi were led by Vincenzo Gioberti (1801–1852), and strongly supported the Pope, whom they considered the moral, spiritual, and political guide towards a united Italy. The neoghibellini favoured a unitary republican state and regarded the Church as an obstacle.

The revolutions of 1848 manifested themselves in Italy with insurrections in Venice, Milan, Tuscany, Naples, and Sicily. They also led to the First War of Independence, between the Kingdom of the Two Sicilies and the Habsburg Empire. The war did not turn out well for the Risorgimento insurgents; after several battles the political situation remained unchanged. The Risorgimento dream nevertheless survived into the following decade, with Count Cavour (1810–1861) emerging as an important political leader in the call for Italian independence. As instigator of the Second War of Independence, which began in 1859, Cavour managed to find an ally in Napoleon III. This war, too, failed to achieve a unified and independent Italy. Infuriated about this, Giuseppe Garibaldi (1807–1882), a native of Nice, marched, together with a thousand volunteers (known as le camicie rosse), to Sicily on 6 May 1860. He managed to take control of that island, which proved the first step in the definitive unification of Italy. When Rome and Venice joined Italy in 1870, the political unification of the newborn state was completed. The position of national capital, which had initially been Turin (1861) and then Florence (1865), was now given to Rome. The Pope in protest declared himself prisoner in his Vatican palace adjoining St Peter’s Basilica, creating a constitutional deadlock not resolved until the Vatican was declared a sovereign state under the Lateran Treaty (1929).

The Risorgimento, opposing as it did the power of the papacy and the Habsburg Empire, was followed with sympathy in Britain and Germany, and had an inspiring effect elsewhere in Europe, not least among nationalities with links to the Italian-based intellectuals ( Albanian, Maltese). Conversely, Catholics in various countries were mobilized for papal support in widespread ultramontanist movements, strengthening the confessionalization of politics in countries like Ireland, France, and the Netherlands.

The independent Italy that was established in 1861 was not, as Mazzini and Garibaldi had envisaged, a republic, but a kingdom, as a successor state to the Kingdom of Sardinia; this was done so as not to antagonize the European monarchies, but embittered Mazzini; Garibaldi was especially aggrieved by the cession of his native Nice to France to procure that country’s acquiescence. Following the political establishment of the Kingdom of Italy, the writer and statesman Massimo D’Azeglio famously declared in 1861 that an Italian Kulturnation now needed to be created (“we have made Italy, now we must make Italians”). The Southern Question, which dealt with the socio-economic and political backwardness of the Italian southern provinces, only increased the experience of an incomplete unification. The creation of a unified nation was pushed forward by cultural-political processes such as the creation of a national historiography, celebrating key figures from the Risorgimento (Mazzini, Garibaldi, and, later, Gabriele D’Annunzio) as national heroes.

The process of redefining and strengthening Italy’s national identity also turned into a quest for the terre irredente (“unredeemed territories”), the ethnically related regions outside the Italian state borders that needed to be redeemed from foreign (Austrian) rule. The ideology and movement of irredentismo aimed at territorial liberation of Trentino-Alto Adige, Istria, and Dalmatia (and also struck a sympathetic chord among the Italophile elite of Malta). These regions had historical ties with the Risorgimento and were considered to be Italian in character; this made the struggle for their “redemption” also a national-regenerative revolution.

The Romantic Nationalist aspirations of the 18th and 19th century Risorgimento project intermingled in the early 20th century with a more modernist form of nationalism, present for example in the political writings and speeches of the poet Gabriele D’Annunzio (who combined post-Romantic aestheticism and Nietzschean titanism in his own writing). From the late 19th into the early 20th century, the cultural and geopolitical struggle of Italian irredentism, together with the celebration of war experiences by Italian avant-gardist circles in the years towards and during the Great War, gave new impetus to the quest for the regeneration of a national Italian identity. It was this context of a melting pot of Romantic and modernist experiences of nationalism that created an opening for the foundations of a Fascist ideology and regime.