Duce is an Italian title, derived from the Latin word dux 'leader', and a cognate of duke. National Fascist Party leader Benito Mussolini was identified by Fascists as Il Duce of the movement since the birth of the Fasci Italiani di Combattimento in 1919. In 1925 it became a reference to the dictatorial position of Sua Eccellenza Benito Mussolini, Capo del Governo, Duce del Fascismo e Fondatore dell'Impero. Mussolini held this title together with that of President of the Council of Ministers: this was the constitutional position which entitled him to rule Italy on behalf of the King of Italy. Founder of the Empire was added for the exclusive use by Mussolini in recognition of his founding of an official legal entity of the Italian Empire on behalf of the King in 1936 following Italy's victory in the Second Italo-Ethiopian War. The position was held by Mussolini until 1943, when he was removed from office by the King and the position of "Duce" was dismantled, while Marshal Pietro Badoglio, 1st Duke of Addis Abeba was appointed Presidente del Consiglio.

The National Fascist Party was a political party in Italy, created by Benito Mussolini as the political expression of Italian fascism and as a reorganisation of the previous Italian Fasces of Combat. The party ruled the Kingdom of Italy from 1922 when Fascists took power with the March on Rome until the fall of the Fascist regime in 1943, when Mussolini was deposed by the Grand Council of Fascism. It was succeeded, in the territories under the control of the Italian Social Republic, by the Republican Fascist Party, ultimately dissolved at the end of World War II.