Ab urbe condita, or anno urbis conditae, abbreviated as AUC or AVC, expresses a date in years since 753 BC, the traditional founding of Rome. It is an expression used in antiquity and by classical historians to refer to a given year in Ancient Rome. In reference to the traditional year of the foundation of Rome, the year 1 BC would be written AUC 753, whereas AD 1 would be AUC 754. The foundation of the Roman Empire in 27 BC would be AUC 727. The current year AD 2024 would be AUC 2777.

The founding of Rome was a prehistoric event or process later greatly embellished by Roman historians and poets. Archaeological evidence indicates that Rome developed from the gradual union of several hilltop villages during the Final Bronze Age or early Iron Age. Prehistoric habitation of the Italian Peninsula occurred by 48,000 years ago, with the area of Rome being settled by around 1600 BC. Some evidence on the Capitoline Hill possibly dates as early as c. 1700 BC and the nearby valley that later housed the Roman Forum had a developed necropolis by at least 1000 BC. The combination of the hilltop settlements into a single polity by the later 8th century BC was probably influenced by the trend for city-state formation emerging from ancient Greece.