Rome transitioned from a monarchy to a republic and eventually became an empire between 753 BC and 476 AD. Key events included the overthrow of the last Etruscan king in 509 BC establishing the Roman Republic, the Punic Wars extending Roman power around the Mediterranean between 246-146 BC, and Octavian taking control and establishing the Roman Empire in 27 BC. The document also discusses aspects of Roman cities including camps becoming cities, infrastructure like roads, bridges, aqueducts, amphitheaters, baths and theaters, and the decline of the Western Roman Empire in 476 AD.