Arch of Trajan Leptis Magna Libya Leptis Magna was one of the most important cities in Roman North Africa attaining the peak of its prominence in the late nd century AD during the reign of the Emperor Septimus Severus who hailed from the city The Arch of Trajan dates from around AD and was built by the citizens of the city in honour of the emperor after he granted the city the status of a colonia after his conquest of Dacia