Ah yes, apologies if I overstated. I should perhaps have said "some people in many parts of Italy still resent...". I'm often told by friends from the south about how the north treated the south during and after unification, and from what I understand there is still a lingering resentment there. I think the point still stands that Italy is not example of a "naturally arisen" national identity anyway.

Source: British person living in Northern Italy with many friends from the South.