Italy, Latin Italia, in Roman antiquity, the Italian Peninsula from the Apennines in the north to the “boot” in the south. In 42 BC Cisalpine Gaul, north of the Apennines, was added; and in the late 3rd century AD Italy came to include the islands of Sicily, Corsica, and Sardinia, as well as Raetia and part of Pannonia to the north.
The first major power in the peninsula were the Etruscans. From Etruria, Etruscan power spread northward to the Po River valley and southward to Campania, but it later collapsed to Etruria itself. Where the Etruscans failed, the people of Rome gradually succeeded in the task of unifying the various Italian peoples into a political whole. By 264 BC all Italy south of Cisalpine Gaul was united under the leadership of Rome in a confederacy; its members were either incorporated in or allied with the Roman state.
The Italian Peninsula is one of the three great peninsulas of southern Europe, the other two being the Balkan (to the east) and the Iberian (to the west). The Italian Peninsula extends from the region of the Po River southward for some 600 miles (960 km); it has a maximum width of 150 miles (240 km). To the east lies the Adriatic Sea, to the south the Ionian Sea, and to the west the Tyrrhenian and Ligurian seas. The Apennines, a volcanic mountain chain subject to frequent earthquakes, extends the length of the peninsula; lowlands are mostly along the coasts. The modern day peninsula comprises much of Italy and includes the independent republic of San Marino as well as Vatican City.