The magnificence of this colony lead the Lucans -an Italic inland people- to try to conquer it. In about 400 B.C. they occupied it and changed its name in Paistom. There the Lucans continued their civil and military activities for a long time, save for a short time as the Greeks of Italy defeated them under the guide of Alexander the Molossian Alexander the Great's uncle- in a battle near Poseidonia in 332 B.C.. In 326 B. C. they regained it after the battle of Pandosia where Alexander died. In the meanwhile another power was extending
itself along the Peninsula: Rome. After the war against Pyrrhus in 273 B.C., it became the uncontested master of these regions and founded there a Latin colony giving it the name of Paestum. The Roman Senat always hold that city in great consideration, because during the war against Hannibal they received assistance -above all victuals- from it. The Romans enriched the city with large buildings, among which there are the portico of the Forum, the thermae, the Amphitheatre, and the so-called Tempio della Pace (Temple of Peace). Paestum flourished till the Late Empire. Because of the changed political exigencies of Rome - turned towards the East - an irreversible crisis begun for the city, like for most of the coast centres. Its inhabitants -converted into Christianity- were reduced to a little community and concentrated next to the Ceres Temple. Others fled to the surrounding hills to avoid malaria, that was spreading there, and the incursions of the Saracens. This explains the birth of a town on the hill, which had a very important strategic and commercial role in the Middle Ages, between the 9th and the 13th centuries, especially during Frederic the Second's reign.
It almost substituted and assumed the role Paestum had had during the ancient times.