Ancient Rome grew from a small settlement into a massive empire between 800 BCE to 500 CE. Key events included the establishment of the Roman Republic in 509 BCE, which established important legal and governmental structures. The Roman Republic then expanded greatly through a series of Punic Wars against Carthage between 264-146 BCE. This established Rome as the dominant power in the Mediterranean. The Roman Empire emerged under Augustus Caesar in 27 BCE and saw the rise of the famous Roman emperors and a period of peace and prosperity known as the Pax Romana. However, by the 5th century CE the Western Roman Empire was beginning to collapse due to invasions from Germanic tribes.