Benito Amilcare Andrea Mussolini (29 July 1883 – 28 April 1945) was an Italian dictator who founded and led the National Fascist Party (PNF). He was Prime Minister of Italy from the March on Rome in 1922, until his deposition in 1943, as well as Duce of Italian fascism from the establishment of the Italian Fasces of Combat in 1919, until his execution in 1945. As a dictator and founder of fascism, Mussolini inspired the international spread of fascist movements during the interwar period.

Mussolini was originally a socialist politician and journalist at the Avanti! newspaper. In 1912, he became a member of the National Directorate of the Italian Socialist Party (PSI), but was expelled for advocating military intervention in World War I. In 1914, Mussolini founded a newspaper, Il Popolo d'Italia, and served in the Royal Italian Army during the war until he was wounded and discharged in 1917. Mussolini denounced the PSI, his views now centering on Italian nationalism, and founded the fascist movement which opposed egalitarianism and class conflict, instead advocating "revolutionary nationalism" transcending class lines. In October 1922, following the March on Rome, Mussolini was appointed prime minister by King Victor Emmanuel III, becoming the then youngest to hold the office. After removing opposition through his secret police and outlawing labour strikes, Mussolini and his followers consolidated power through laws that transformed the nation into a one-party dictatorship. Within five years, Mussolini established dictatorial authority by legal and illegal means and aspired to create a totalitarian state. In 1929, Mussolini signed the Lateran Treaty with the Holy See, to establish the Vatican City.