Italy officially the Italian Republic; Italian: Repubblica Italiana, IPA is a country located in Southern Europe, that comprises the Po River valley, the Italian Peninsula and the two largest islands in the Mediterranean Sea, Sicily and Sardinia. It is also called by Italians lo Stivale, or la Penisola . Italy shares its northern alpine boundary with France, Switzerland, Austria and Slovenia. The independent countries of San Marino and the Vatican City are enclaves within Italian territory, while Campione d'Italia is an Italian exclave in Switzerland. Italy was home to many well-known and influential European cultures, including the Etruscans, Greeks, and the Romans. Its capital Rome has been a historically important world city, especially as the core of ancient Rome and the Roman Catholic Church. For more than 3,000 years Italy experienced migrations and invasions from Germanic, Celtic, Frankish, Lombard, Byzantine Greek, Saracen and Norman peoples during the Middle Ages, followed by the Italian Renaissance period, in which the Italian Wars took place and various city-states were noted for their cultural achievements.