Narni was a town of the ancient Umbrians under the name Nequinum, and it was known already in the 7th century BC. Conquered by the Romans in the 4th century BC, was Narnia after the nearby Nar River. In 209 BC, it was destroyed by the Romans, for refusing to help pay for the war against Carthage. It was later rebuilt as an outpost for the legions of Rome along the Via Flaminia which connected the city of Rome to the Adriatic Sea.
In the Middle Ages, Narni protected the edges of the Papal States. It was plundered in 1527 by the German mercenaries (Landsknechten, Lanzichenecchi in Italian) in the army of Charles V.