The Kingdom of Italy (Italian: Regno d'Italia) was a state which existed from 1861—when King Victor Emmanuel II of Sardinia was proclaimed King of Italy—until 1946—when a constitutional referendum led civil discontent to abandon the monarchy and form the modern Italian Republic. The state was founded as a result of the unification of Italy under the influence of the Kingdom of Sardinia, which can be considered its legal predecessor state.
Reference: Wikipedia:Kingdom of Italy