The various Italian states are ruled by either the papacy, the Bourbons or the Habsburgs.
The first of the European revolutions of 1848 begins in Palermo as a popular insurrection.
Soon taking on overtones of Sicilian separatism, it spreads throughout the island and, eventually, the entire peninsula.
When the dust settles some twenty-two years later, Italy will have become a single nation united under a hereditary monarch who is neither Bourbon or Habsburg, and the pope will have imprisoned himself in his sole remaining enclave, the Vatican City.