While Catalonia is fighting with Madrid over its independence movement, Italy is surprisingly calm, at least on the front of secessionist movements, despite a history suggesting the opposite.
Italy became a united State only in the XIX century, when the Kingdom of Piedmont-Sardinia absorbed many century-old little and medium States.
There were of course resistances, especially in the South which greeted enthusiastically the Italian troops, but after centuries of laissez-faire by the Bourbons was shocked by the efficiency of Turin (and later Rome) in collecting taxes and drafting conscripts.
In the chaos which followed the 1943 Armistice, Sicily and Sardinia went on the verge of unilateral independence, while Trentino Alto Adige was (quite willingly) temporarily annexed by Germany.
In more recent times, there were some secessionist initiatives especially in the richest Northern regions, but without too much vigor or popular support.