The course intends to retrace the processes of profound political, economic and social transformations which, in the aftermath of the First World War and the Russian Revolution, have provoked, on the one hand, the mobilization of popular classes and the affirmation of mass parties and, on the other, the eruption of nationalistic unrest and the success of totalitarian ideologies. After documenting the instability of the institutional framework and the inability of the ruling classes to fully understand the nature of reactionary movements, the course will examine the different causes of the birth and advent of Italian fascism, from the first civil war to the dictatorship.