The Third War of Independence ends: after its proclamation, the Kingdom of Italy sought to complete territorial unification through the conquest of Veneto (held by Austria) and Papal Lazio. With the Third War of Independence (June 20–August 23, 1866), Veneto was acquired: Italy exploited the conflict between Austria and Prussia, with whom it was bound by both an offensive and defensive alliance. Italian troops were defeated by Austrian troops both on land (Custoza) and at sea (Lissa), and only Prussia’s victory forced Austria to cede Veneto. But the annexation occurred ingloriously: Austria handed Veneto over to France, which in turn ceded it to Italy. Finally, on October 3, 1866, the Italo-Austrian peace treaty was signed, by which the Austrian Empire recognized the Kingdom of Italy. The country thus completed its territorial unification, from which only Rome (which was conquered on 20 September 1870) and Trento remained excluded.
