ローマ建国紀元
"Ab urbe condita", literally "From the founding of the city", describes the Roman tradition of beginning histories at the founding of the city of Rome. In Livy's "Ab Urbe Condita", much time is spent on the early history of Rome, and on the founding of the city itself. In Sallust's histories, the founding and early history of Rome is almost reduced to a single sentence. Thus, the "ab urbe condita" form is extremely variable while continuing to mould Roman histories.