Oppidum - 194 BC

 An oppidum was a large fortified Iron Age settlement or town create by Celtic. The Celtic settlements continued to be used until the Romans conquered Southern and Western Europe. 

In 194 BC a group of three hundred Roman citizens, with their respective families, settled on the slopes of an impervious hill in the northern part of the Sele plain (Ager Picentinus), giving rise to the city of Salernum. 

According to the historian Tito Livio, the foundation of this new colony takes place in a pre-existing fortified center , with the aim of garrisoning the territory previously inhabited by the Picentini. A Roman city worthy of the name had to have an amphitheater, forum, temples, theater, baths, aqueducts and, more generally, a building aspect of a certain type, with straight streets that crossed at right angles, possibly well paved and equipped with a sewer system, lined with brick houses.

Subsequently other settlers were sent to Salerno and in 199 BC Scipio transformed the Salerno maritime portorium into state customs. The aim of keeping the Picentini rebels in check justified the new direct Roman dominion in the gulf, which already belonged to Paestum, without arousing mistrust on the part of the nearby colonies and allied cities of Latin law. Among these we must include not only the very faithful Latin colony of Paestum, but also the ancestor of Roman Salerno, that is the ancient Etruscan city (Irnthi), to which the military aid provided in Rome before the battle of Canne must be referred. All this attention for Salerno on the part of Rome presupposes an economic and mercantile prosperity which is, in fact, attested by the pre-Roman archaeological materials discovered in the necropolis and in the ancient town, at the mouth of the Irno valley, in the Fratte district (Irnthi).

Once Paestum also decayed and the commercial function of the roman Porto Alburnus at the mouth of the Sele near the Heraion ceased, the sinus Paestanus will finally become the gulf of Salerno.

During the war between Rome and the Italic allies (Socii), the so-called “Social War” (91-88 BC), the rebel army, led by Papius Mutilus, conquered Salernum and enlisted slaves and prisoners.

"Salernum vetusta urbs, sita olim paulum supra mare" used to say Strabone (60 BC – 24 AD), so the ancient Salerno was built on the heights of the hill that dominates it, and not just close to the sea. Compared to the castrum, the city is located towards the sea, up to the south of the current via dei Mercanti, and expands towards the west, up to the course of the Fusandola stream, and towards the east, up to the outlet of the same via dei Mercanti on today's wide Sedile di Portanova. Perhaps the forum has been set up off Largo Abate Conforti, certainly in the area today of San Pietro a Corte the baths are built and the necropolis is located beyond the eastern walls.

The earthquake in 79 AD damaged also Salernum. The restoration works to public buildings, thanks to emperor Titus’ intervention, are linked to this circumstance and there is also a reference to them in an inscription found in 1948 in the necropolis of Vittorio Emanuele Avenue.

Under the Emperor Diocletian, in the late 3rd century AD, Salernum became the administrative centre of the Bruttia and Lucania province.

An important period in the life of Salernum seems to be the age of Constantine (306-337 AD). Two statue bases have been found in Largo Abate Conforti, perhaps corresponding to the tribunal area, one related to a statue dedicated by the city senate to emperor Constantine, the other put in honor of his mother Elena by Alpinio The Great, governor (corrector) of the province of Bruttia and Lucania

Between the end of the 4th century and the early 5th century AD, a calamity shocked Salernum. A strong flood caused by a stream that passed through the urban area made the situation so difficult that many people chose to leave the city. Following these floods, it has always been preferred not to remove the layers originated by the disastrous events but to carry out a series of fillings; it resulted in an often insurmountable obstacle for archaeological investigation.