The oldest pottery from the Castrum has been dated to the period 380-340 BC. According to Filippo Coarelli the fortress is as old as the late fifth century BC, in view of the origin of the tufa (from Fidenae).According to Archer Martin it has to be dated to 300-275 BC, because pottery found next to the foundation of the walls belongs to that period.The existence of the settlement is likely, because Livius mentions Ostia twice in his accounts of the fifth century.Livy mentions floods of the Tiber in 414 and 363 BC (AUC 4.49.2-3 and 7.3.2).Here is a historical introduction to Ostia, the necessary background to understand this website.The page covers early Ostia, Ostia's hey-day, late antiquity, the Middle Ages, and the history of the excavations.
Data were mainly collected from drillings, which were then interpreted from the sedimentological and paleobotanical viewpoint.Therefore Ostia is today still lying next to the Tiber, but at a distance of some three kilometers from the beach.Ostia is Latin for "mouth", the mouth of the Tiber.On the plan it is also called Via Laurentina, a road leading to the south-east to the village Laurentum. The rectangle is a military fortress that was built later, probably in the early third century (see below). The oldest settlement that has been found is the so-called Castrum.To the south of the fortress the old road continues ("southern stretch of the Cardo"). It was a rectangular, military fortress (194 x 125.7 metres), with walls of large tufa blocks.