Amadeo I (Italian Amedeo, sometimes anglicized as Amadeus) (30 May 1845 – 18 January 1890) was the only King of Spain from the House of Savoy. He was the second son of King Vittorio Emanuele II of Italy and was known for most of his life as the Duke of Aosta, but reigned briefly as King of Spain from 1870 to 1873.