Giuseppe Mazzini in the context of "Italian Republican Party"

The Unification of Italy (Italian: Unità d'Italia [uniˈta ddiˈtaːlja]), also known as the Risorgimento (Italian: [risordʒiˈmento]; lit. 'Resurgence'), was the 19th century political and social movement that in 1861 ended in the annexation of various states of the Italian peninsula and its outlying isles to the Kingdom of Sardinia, resulting in the creation of the Kingdom of Italy. Inspired by the rebellions in the 1820s and 1830s against the outcome of the Congress of Vienna, the unification process was precipitated by the Revolutions of 1848, and reached completion in 1870 after the capture of Rome and its designation as the capital of the Kingdom of Italy.

Individuals who played a major part in the struggle for unification and liberation from foreign domination included King Victor Emmanuel II; politician, economist and statesman Camillo Benso, Count of Cavour; general Giuseppe Garibaldi; and journalist and politician Giuseppe Mazzini. Borrowing from the old Latin title Pater Patriae of the Roman emperors, the Italians gave to King Victor Emmanuel II the epithet of Father of the Fatherland (Italian: Padre della Patria). Even after 1870, many ethnic Italian-speakers (Italians in Trentino-Alto Adige/Südtirol, Savoyard Italians, Corfiot Italians, Niçard Italians, Swiss Italians, Corsican Italians, Maltese Italians, Istrian Italians, and Dalmatian Italians) remained outside the borders of the Kingdom of Italy, planting the seeds of Italian irredentism.

The Expedition of the Thousand (Italian: Spedizione dei Mille) was an event of the unification of Italy that took place in 1860. A corps of volunteers led by Giuseppe Garibaldi sailed from Quarto al Mare near Genoa and landed in Marsala, Sicily, in order to conquer the Kingdom of the Two Sicilies, ruled by the Spanish House of Bourbon-Two Sicilies. The name of the expedition derives from the initial number of participants, which was around 1,000 people.

The Garibaldians, with the contribution of southern volunteers and reinforcements to the expedition, increased in number, creating the Southern Army. After a campaign of a few months with some victorious battles against the Bourbon army, the Thousand and the newborn southern army managed to conquer the entire Kingdom of the Two Sicilies. The expedition was a success and concluded with a plebiscite that brought Naples and Sicily into the Kingdom of Piedmont-Sardinia, the last territorial conquest before the proclamation of the Kingdom of Italy on 17 March 1861. The Expedition of the Thousand was the only desired action that was jointly decided by the four "Fathers of the Fatherland": Giuseppe Mazzini, Giuseppe Garibaldi, King Victor Emmanuel II, and Camillo Benso, Count of Cavour, pursuing divergent goals. Mazzini, of republican political belief, wanted to liberate Southern Italy and Rome, while Garibaldi wanted to conquer, in the name of Victor Emmanuel II, the Kingdom of the Two Sicilies and continue towards Rome to complete the Italian unification, while Cavour wanted to prevent the conquest of Rome to avoid a conflict with his French ally, Napoleon III, who protected the Papal States.

Giuseppe Maria Garibaldi (/ˌɡærɪˈbɑːldi/ GARR-ib-AHL-dee, Italian: [dʒuˈzɛppe ɡariˈbaldi] ; 4 July 1807 – 2 June 1882) was an Italian general, revolutionary and republican. He contributed to the Unification of Italy (Risorgimento) and the creation of the Kingdom of Italy. He is considered to be one of Italy's "fathers of the fatherland", along with Camillo Benso di Cavour, King Victor Emmanuel II and Giuseppe Mazzini. Garibaldi is also known as the "Hero of the Two Worlds" because of his military enterprises in South America and Europe.

Garibaldi was a follower of the Italian nationalist Mazzini and embraced the republican nationalism of the Young Italy movement. He became a supporter of Italian unification under a democratic republican government. However, breaking with Mazzini, he pragmatically allied himself with the monarchist Cavour and Kingdom of Sardinia in the struggle for independence, subordinating his republican ideals to his nationalist ones until Italy was unified. After participating in an uprising in Piedmont, he was sentenced to death, but escaped and sailed to South America, where he spent 14 years in exile, during which he took part in several wars and learned the art of guerrilla warfare. In 1835 he joined the rebels known as the Ragamuffins (farrapos), in the Ragamuffin War in Brazil, and took up their cause of establishing the Riograndense Republic and later the Catarinense Republic. Garibaldi also became involved in the Uruguayan Civil War, raising an Italian force known as Redshirts, and is still celebrated as an important contributor to Uruguay's reconstitution.

Italian nationalism (Italian: Nazionalismo italiano) is a movement which believes that the Italians are a nation with a single homogeneous identity, and therefrom seeks to promote the cultural unity of Italy as a country. From an Italian nationalist perspective, Italianness is defined as claiming cultural and ethnic descent from the Latins, an Italic tribe which originally dwelt in Latium and came to dominate the Italian peninsula and much of Europe. Because of that, Italian nationalism has also historically adhered to imperialist theories.

Italian nationalism is often thought to trace its origins to the Renaissance, but only arose as a political force in the 1830s under the leadership of Giuseppe Mazzini. It served as a cause for Risorgimento in the 1860s to 1870s. Italian nationalism became strong again in World War I with Italian irredentist claims to territories held by Austria-Hungary, and during the era of Italian Fascism.

Young Italy (Italian: La Giovine Italia, pronounced [la ˈdʒoːvine iˈtaːlja]) was an Italian political movement founded in 1831 by Giuseppe Mazzini. A few months after leaving Italy, in June 1831, Mazzini wrote a letter to King Charles Albert of Sardinia, in which he asked him to unite Italy and lead the nation. A month later, convinced that his demands did not reach the king, he founded the movement in Marseille. It would then spread out to other nations across Europe. The movement's goal was to create a united Italian republic through promoting a general insurrection in the Italian reactionary states and in the lands occupied by the Austrian Empire. Mazzini's belief was that a popular uprising would create a unified Italy. The slogan that defined the movement's aim was "Union, Strength, and Liberty". The phrase could be found in the tricolor Italian flag, which represented the country's unity.