The leader known for the unification of Italy in the 19th century is Giuseppe Garibaldi. He was a key figure in the Italian Risorgimento, the movement that led to the unification of various independent states on the Italian peninsula into a single nation-state. Garibaldi is best known for his military campaigns, including the famous Expedition of the Thousand in 1860, where he led a volunteer army to conquer Sicily and southern Italy. His efforts, along with those of other leaders like Count Camillo di Cavour and King Victor Emmanuel II, ultimately contributed to the proclamation of the Kingdom of Italy in 1861.