Il Popolo d'Italia Fasci Fasci Italiani di Combattimento Italian Austria-Hungary
Mussolini, a syndicalist who supported the war on grounds of irredentist claims on Italian-populated regions of Austria-Hungary, formed the pro-interventionist Il Popolo d'Italia and the Fasci Rivoluzionario d'Azione Internazionalista ("Revolutionary Fasci for International Action") in October 1914 that later developed into the Fasci Italiani di Combattimento in 1919, the origin of fascism.