XD
Well in a nutshell. Italy was unified in 1870 under Liberal government. After many failed attempts to please the Nationalists (losing the battle of Adowa, disputes with Austra and the Libya incidents) and the Socialists (Liberals kept trying to please the Nationalists) they signed a treaty with Britain, France and Russia in the first World War that promised them some land. This was a betrayal against Germany and Austria.
In the Paris peace conference, after the war, they were given the land but not the one they wanted: Fiume. This angered the Nationalists (Particularly Mussolini and D'annunzio) and D'annunzio led a march on Fiume. Mussolini copied his way of leadership and violence to lead the march on Rome. Thus, Fascism is born.
I just typed that didn't I?