River Tiber in the context of "Ancient Rome"

In modern historiography, ancient Rome is the Roman civilisation from the founding of the Italian city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 BC), the Roman Republic (509‍–‍27 BC), and the Roman Empire (27 BC – 476 AD) until the fall of the western empire.

Ancient Rome began as an Italic settlement, traditionally dated to 753 BC, beside the River Tiber in the Italian Peninsula. The settlement grew into the city and polity of Rome, and came to control its neighbours through a combination of treaties and military strength. It eventually controlled the Italian Peninsula, assimilating the Greek culture of southern Italy (Magna Graecia) and the Etruscan culture, and then became the dominant power in the Mediterranean region and parts of Europe. At its height it controlled the North African coast, Egypt, Southern Europe, and most of Western Europe, the Balkans, Crimea, and much of the Middle East, including Anatolia, the Levant, and parts of Mesopotamia and Arabia. That empire was among the largest empires in the ancient world, covering around 5 million square kilometres (1.9 million square miles) in AD 117, with an estimated 50 to 90 million inhabitants, roughly 20% of the world's population at the time. The Roman state evolved from an elective monarchy to a classical republic and then to an increasingly autocratic military dictatorship during the Empire.