The Italian unification (Italian: il Risorgimento, or "The Resurgence") was the political and social movement that unified different states of the Italian peninsula into the kingdom of Italy. There is a lack of consensus on the exact dates for the beginning and the end of Italian unification, but many scholars agree that the process began with the end of Napoleonic rule and the Congress of Vienna in 1814, and approximately ended with the Franco-Prussian War in 1871 and the conquest of Rome, though Trento and Triest (the last "città irredente", cities that Italian nationalists considered as Italian under foreign domination) did not join the Kingdom of Italy until after World War I.