Italian irredentism (Italian: irredentismo italiano) was a nationalist movement during the late 19th and early 20th centuries in Italy with irredentist goals which promoted the unification of geographic areas in which indigenous ethnic Italians and Italian-speaking persons formed a majority, or substantial minority, of the population.
Originally, the movement promoted the annexation to Italy of territories inhabited by an Italian indigenous population but retained by the Austrian Empire after Third Italian War of Independence in 1866.
During the period of Risorgimento in 1860 to 1861, Prime Minister of Piedmont-Sardinia, Camillo Benso, Count of Cavour who was leading the Risorgimento effort, faced the view of French Emperor Napoleon III who indicated that France would support militarily the Italian unification provided that France was given Nice and Savoy that were held by Piedmont-Sardinia, as France did not want a powerful state having control of the passages of the Alps. As a result, Piedmont-Sardinia was pressured to concede Nice and Savoy to France in exchange for France accepting and sending troops to help the unification of Italy. These included Trentino and Trieste, but also multilingual and multiethnic areas within the northern Italian region encompassed by the Alps, with German, Italian, Slovene, Croatian, Ladin and Istro-Romanian population such as South Tyrol, a part of Istria, Gorizia and Gradisca, and part of Dalmatia. The claims were extended later to the city of Fiume, Corsica, the island of Malta, the County of Nice, and Italian Switzerland.