In the high Middle Ages, a notable commercial, cultural and political fortune, of which the glories of the homonymous Lombard and Norman Principality are outstanding historical testimony, as well as the famous Medical School. The urban aspect of the city of Salerno during the Middle Ages has grown in the direction of the low-hill part of the civic territory, inside the walls of the Arechi Castle, still visible today. Only at the end of the eighties, mainly thanks to the archaeological investigation which began to unveil a picture of the early medieval city and the interventions of Arechi II substantially adherent to the testimony of Paolo Diacono in the Historia Langobardorum.

The senatorial nobility was still present in the city after the fall of the Western Roman Empire in 476 AD, as the inscription attests sepulchral of Senator Socrates "vir spectabilis" who died in 497 AD in Salerno and buried in the cemetery that occupied the space of the imperial baths from around the middle of the century that emerged under S. Pietro a Corte.

In any case, also Salerno had lived as other cities the long period of readjustment and, before the Lombards of Benevento conquered it (around 640 AD), it had gravitated towards the Byzantine orbit, under the Duke of Naples.