The promontory on which Agropoli is was inhabited since Bronze and Iron Ages by populations that lived fishing and hunting.
In VI century, during the Greek-Gothic war (535-553), Byzantines needed a safe port in the Southern part of Salerno and so they fortified this place calling it Acropolis, that is “a town situated in a high position”.
At the end of VI century, Longobard invasion made the bishop of Paestum take refuge in Agropoli. Agropoli became the Episcopal seat and all the survivors of Byzantine territories moved there.
Agropoli was inhabited by Byzantines until 882 when Saracens arrived and fortified the town.
The bishop controlled the town in the following years: they had also Eredita and Ogliastro. This whole territory formed the feud of Agropoli that belonged to the bishops of Capaccio until XV century. Then Agropoli belonged to Sanseverino family until 1552 when Ferrante lost all the properties of the family because he was accused of betrayal.
Agropoli was then ruled by D'Ayerbo d'Aragona (1553), Grimaldi (after 1564), Arcella Caracciolo (1597), Mendoza (1607), Filomarino princes of Roccadaspide (1626), Mastrillo (1650), Zattara and eventually Sanfelice dukes of Laureana (1660), who ruled the town until the end of feudalism (1806).