Italian unification was the nineteenth century political process through which numerous independent states and territories on the Italian peninsula were progressively brought together into a single Kingdom of Italy. The process is commonly called the Risorgimento, a term meaning resurgence or revival, although the Risorgimento encompassed cultural, political, intellectual and military developments extending beyond the formal creation of the kingdom.
Before unification, the peninsula was divided among the Kingdom of Sardinia, the Kingdom of the Two Sicilies, the Papal States, the Grand Duchy of Tuscany, the Duchies of Parma and Modena, and other smaller territories, while Austria exercised direct or indirect control over important northern Italian territories. Italian unification therefore involved the defeat or removal of foreign influence, the annexation or voluntary incorporation of existing Italian states, diplomatic agreements, popular uprisings and military campaigns. The movement was not controlled by one person or one ideology. Giuseppe Mazzini promoted republican nationalism, Count Cavour pursued diplomatic and constitutional state building, Giuseppe Garibaldi led military campaigns, and Victor Emmanuel II provided the monarchy around which the new kingdom was constructed.
The intellectual background of Italian unification developed during the era of nationalism that followed the French Revolution and Napoleonic Wars. Napoleon had reorganised much of Italy into larger political units and introduced administrative, legal and social changes that weakened some older territorial divisions. After Napoleon's defeat, the Congress of Vienna in 1815 restored many traditional rulers and divided the peninsula again, while Austria became the dominant foreign power in northern Italy.
Nationalists increasingly argued that Italians shared linguistic, cultural and historical connections that should be expressed through political unity. The concept of an Italian nation remained contested because regional dialects, political traditions, economic structures and local identities differed substantially. Literacy, urbanisation, economic development and the spread of newspapers, political associations and nationalist literature helped create a broader sense of Italian national identity. Secret societies and revolutionary groups, including the Carbonari, participated in earlier attempts to challenge established governments. Revolutions in 1820, 1830 and 1848 demonstrated the strength of nationalist and liberal opposition but also exposed the military and political difficulties involved in unification.
The revolutions of 1848 were particularly important because nationalist and liberal movements challenged Austrian rule and conservative governments across Europe. In the Italian states, revolutionary movements demanded constitutions, political reform and national independence. Charles Albert, King of Sardinia, declared war on Austria in 1848, but Sardinian forces were defeated. The revolutions were eventually suppressed, and Austria retained considerable influence in northern Italy. Nevertheless, the failure of 1848 helped demonstrate that a successful unification strategy required more than spontaneous revolutionary activity.
The Kingdom of Sardinia, centred on Piedmont and including Genoa and Sardinia, subsequently became the leading constitutional Italian state and the principal base for Cavour's strategy. The survival of its parliamentary institutions gave it diplomatic credibility and allowed its government to seek alliances with major European powers. The Crimean War provided an opportunity for Sardinia to participate in European diplomacy, and Cavour used the resulting international position to raise the Italian question at the Congress of Paris in 1856.
Cavour's strategy was central to the northern phase of unification. As prime minister of Piedmont Sardinia, he promoted economic modernisation, infrastructure, military reform and diplomatic engagement. He recognised that Sardinia could not defeat Austria alone and therefore sought French support. The secret agreement at Plombières in 1858 between Cavour and Napoleon III established the basis for French assistance against Austria. War followed in 1859, and Franco Sardinian forces defeated Austria at battles including Magenta and Solferino.
Austria surrendered Lombardy, which was transferred to Sardinia, although Napoleon III unexpectedly ended the war before the complete removal of Austrian influence from northern Italy. Central Italian states subsequently experienced uprisings and plebiscites that favoured incorporation into Sardinia. These developments demonstrated the importance of both military victory and political mobilisation. Cavour's approach differed significantly from Mazzini's revolutionary republicanism because Cavour sought unification through the expansion of the constitutional monarchy rather than through a democratic republic.
Garibaldi's expedition of 1860 transformed the unification process by bringing the southern Italian mainland and Sicily under the control of the nationalist movement. Garibaldi assembled approximately one thousand volunteers, popularly known as the Thousand, and sailed from Genoa to Sicily. After defeating Bourbon forces at several engagements, his forces gained control of Sicily. Garibaldi then crossed to the Italian mainland and advanced towards Naples. The Bourbon monarchy collapsed, and Garibaldi entered Naples.
His success created a potential political problem because he was a republican sympathiser and could have attempted to establish an independent southern state. Instead, he agreed to hand his conquests to Victor Emmanuel II. A meeting between Garibaldi and the king took place at Teano in October 1860, symbolising the transfer of authority. Plebiscites subsequently supported annexation of the territories into the expanding Kingdom of Sardinia. This sequence brought most of the Italian peninsula under the monarchy while preventing the southern campaign from developing into a separate revolutionary government.
The first Kingdom of Italy was proclaimed on 17 March 1861, with Victor Emmanuel II becoming king of Italy. However, unification was not yet territorially complete. Venetia remained under Austrian control, and Rome remained within the Papal States under the protection of French troops. Italy acquired Venetia in 1866 after siding with Prussia during the Austro Prussian War. Italian forces were not particularly successful militarily in that conflict, but Austria's defeat by Prussia forced the transfer of Venetia to Italy.
Rome remained the final major territorial question. When the Franco Prussian War began in 1870, Napoleon III withdrew French troops from Rome because they were needed for the war. Italian forces entered Rome in September 1870 after limited resistance, and Rome was annexed to Italy. A plebiscite subsequently supported incorporation, and Rome became the capital in 1871. The capture of Rome is commonly regarded as the completion of Italian unification, although tensions between the Italian state and the papacy continued for decades.
Italian unification produced a political state but did not immediately create a socially or economically homogeneous nation. The new kingdom incorporated regions with very different levels of industrialisation, infrastructure, literacy and agricultural organisation. Northern Italy generally possessed greater industrial development and stronger commercial networks, while large parts of the south were predominantly agricultural and experienced widespread poverty and limited infrastructure. The government faced the challenge of creating common taxation, military service, legal administration, education and transport systems.
Standard Italian was not the everyday language of much of the population, who commonly spoke regional languages and dialects. National identity therefore had to be constructed through schools, military service, public administration, symbols, monuments and national institutions. The phrase attributed to Massimo d'Azeglio, that Italy had been made and Italians still had to be made, captures a major historical problem, although the exact wording and context require careful treatment. Political unity was therefore only one stage in the much longer development of Italian national identity.
The Papacy's relationship with the new Italian state became one of the most significant unresolved consequences of unification. Pope Pius IX rejected the loss of the Papal States and considered himself deprived of his territorial sovereignty after Rome was incorporated into Italy. The Law of Guarantees of 1871 attempted to define the pope's position and provide protections and privileges, but the papacy did not accept the settlement as a satisfactory resolution.
The resulting Roman Question remained unresolved until the Lateran Treaty of 1929, when the Kingdom of Italy and the Holy See established the independent Vatican City and settled outstanding disputes. Italian unification therefore transformed not only the political map of the peninsula but also the relationship between state and Church. The new kingdom became a constitutional monarchy, but its political system remained limited by property qualifications and other restrictions during the early decades. Electoral participation gradually expanded over subsequent generations. Unification also changed Italy's position within Europe, creating a new medium sized European power whose governments subsequently pursued colonial, military and diplomatic ambitions.
