Which Royal House ruled Italy between 1861 and 1946?

The House of Savoy (Italian: Casa Savoia) is a royal dynasty that was established in 1003 in the historical Savoy region. Through gradual expansion, the family grew in power from ruling a small county in the Alps north-west of Italy to absolute rule of the kingdom of Sicily in 1713 to 1720 (exchanged for Sardinia).

Through its junior branch (the House of Savoy-Carignano) it led the unification of Italy in 1861 and ruled the Kingdom of Italy from 1861 until 1946 and, briefly, the Kingdom of Spain in the 19th century. The Savoyard kings of Italy were Victor Emmanuel II, Umberto I, Victor Emmanuel III, and Umberto II. The last monarch ruled for a few weeks before being deposed following the Constitutional Referendum of 1946, after which the Italian Republic was proclaimed.

The name derives from the historical region of Savoy in the Alpine region between what is now France and Italy. Over time, the House of Savoy expanded its territory and influence through judicious marriages and international diplomacy. From rule of a small region on the French/Italian border, the dynasty's realm grew to include nearly all of the Italian Peninsula by the time of its deposition.