Owing to Italy’s rather late (by European standards) unification, the concept of nation-state has not yet got assimilated by “flesh and blood” of the country’s political system. And, though Italy is far from facing the problem of armed separatism, the country encountered a serious challenge to its unity and territorial integrity in 1990s to 2000s. In the political scene, this challenge happened to be evinced by the activity of the “League of the North” being headed by Umberto Bossi. The article contains analysis of this organization’s theoretical orientations, as well as of the reasons for which the League has gained popularity with the electors in a number of the country’s regions. In the author’s estimation, the most important one among these reasons is Italy’s deepening internal heterogeneity conducive to the country’s ever greater regionalization. Political result of this process expressed itself in a large scale constitutional reform that created conditions for Italian regions actively making their way to the world arena.