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.