Tiber Valley in the context of "Rome"

Rome is the capital city and most populated comune (municipality) of Italy. It is also the administrative centre of the Lazio region and of the Metropolitan City of Rome. A special comune named Roma Capitale with 2,746,984 residents in 1,287.36 km (497.1 sq mi), Rome is the third most populous city in the European Union by population within city limits. The Metropolitan City of Rome Capital, with a population of 4,223,885 residents, is the most populous metropolitan city in Italy. Its metropolitan area is the third-most populous within Italy. Rome is located in the central-western portion of the Italian Peninsula, within Lazio (Latium), along the shores of the Tiber Valley. Vatican City (the smallest country in the world and headquarters of the worldwide Catholic Church under the governance of the Holy See) is an independent country inside the city boundaries of Rome, the only existing example of a country within a city. Rome is often referred to as the City of Seven Hills due to its geography, and also as the "Eternal City". Rome is generally considered to be one of the cradles of Western civilization and Western Christian culture, and the centre of the Catholic Church.

Rome's history spans 28 centuries. While Roman mythology dates the founding of Rome at around 753 BC, the site has been inhabited for much longer, making it a major human settlement for over three millennia and one of the oldest continuously occupied cities in Europe. The city's early population originated from a mix of Latins, Etruscans, and Sabines. Eventually, the city successively became the capital of the Roman Kingdom, the Roman Republic and the Roman Empire, and is regarded by many as the first-ever Imperial city and metropolis. It was first called The Eternal City (Latin: Urbs Aeterna; Italian: La Città Eterna) by the Roman poet Tibullus in the 1st century BC, and the expression was also taken up by Ovid, Virgil, and Livy. Rome is also called Caput Mundi (Capital of the World).