Looking at maps of the Holy Roman Empire, the states of Northern Italy like Savoy, Milan, Genoa, Florence, Siena, etc. are almost always included, but by the time of the Treaty of Westphalia, the only part that's ever included is Savoy Proper. I can find very little on this. Did the duchies and city-states of Italy ever declare independence, like the United Provinces and the Swiss Confederacy? Or was there just a gradual acceptance that Imperial jurisdiction no longer applied?