The unofficial Peperoncino Line runs across the northern border of the Abruzzo and reaches the Tyrrhenian somewhere north of Rome. North of it most people would make the sign of the cross at the mere mention of hot peppers. Down south, people have been using them to spice up simple pasta and pizza dishes for centuries.
But not that many years ago, you wouldn't ever see hot peppers on a restaurant even in the south, though if you looked like the right sort of foreigner a waiter might inquire discreetly if the signore would like a little something extra in his sauce.
Peperoncini, or diavoletti as they are sometimes called, were long looked down on as peasant food, something disagreeable that only masked the delicate tastes of good cooking. But after some centuries out of fashion they're making a big comeback, even north of the Line. Now there's even an academy, the Accademia Italiana del Peperoncino, and a National Peperoncino Festival (at Diamante in Calabria, early September).
Italy has over 200 varieties of peperoncino, most of them of moderate strength, like the small red soverato and pepino calabro of Calabria or the bacio di satana (Satan's kiss) from the Abruzzo. Increasingly, cooks are trying the hotter ones from the tropics. South Italians put peperoncini in stews and pasta sauces, notably in the famous Roman penne all'arrabbiata. They preserve them sott'olio, or else they dry them to make the tasty pepper flakes you see in every pizzeria.
Modica in Sicily, which has been famous for chocolate since the Spaniards first brought it over, is where chocolate first teamed up with chilis in Europe—from an old Aztec recipe, they say.