The sausage may have been invented by the Lucanians, the ancient people of the Basilicata. Roman soldiers carried it all over the Mediterranean, and it survives as the Spanish longaniza and Greek loukaniko.
In Puglia and the south it's usually lucanica. Up north, luganega is a famous dish in Lombardy, especially the version made in Monza; it's often served with a risotto. In truth the name covers dozens of different sausages, but most will have a bit of cheese and garlic in the mix, and lots of spice, especially fennel seed. Local versions might have rice, hot peppers, tomato, wine, etc; some are smoked.
The Luganega trentina is the Ark of Taste.
Images by: Dana Facaros and Michael Pauls