Looking back at the eventual role of Ostia, it seems to be a logical assumption that Ostia was originally built to serve the above-mentioned purpose: to be a harbour city for Rome. Florus, in his work Historiae Romanae Epitomae, gives us this exact narrative:
He [Ancus Marcius] also planted a colony at Ostia where the sea and river join, even then evidently foreseeing that it would form as it were the maritime store-house of the capital and would receive the wealth and supplies of the whole world.
(Florus, Epitomae Historiae Romanae, I.1.4)
Murky origins
Cicero also claims that Ostia was founded by the legendary fourth king of Rome, Ancus Marcius ( II.3.5, II.18.33). Livy provides additional information, claiming that salt drying fields were also built next to the colony of Ostia (, I.33). These sources refer to Ostia as a colony, but the archaeological evidence points towards the existence, a fort, which can be dated to the fourth century BC.
