SLOW DECAY AND SLOW EMERGENCE
Ancient Ostia was not frozen in time, like Pompeii and Herculaneum. Neither is it part of a living and changing city, like Rome. The city was abandoned slowly, and collapsed slowly. It was also brought to light slowly. Both processes took centuries.
The determining factors for the abandoning of the city were political instability, the decline of the economy, the diminishing role of Rome, and eventually the collapse of the Roman empire. The situation changed dramatically after the first quarter of the fifth century. In 410 AD Alaric with Goths, Huns and Alans sacked Rome. In 409 AD he also captured Portus, but ignored Ostia. In 455 AD Gaeseric and the Vandals sacked Portus. An inscription informs us that they burned the church of Saint Hippolytus on the Isola Sacra, the island between Ostia and Portus. Perhaps they also plundered Ostia. In 537 Vitigis and the Goths laid siege to Portus. Belisarius defended Portus, but also Ostia, that was now used as harbour because Portus was held by the Goths.
Around 600 AD the number of people living in Ostia and in Portus, its harbour district, was negligable. It was the end of a process of decay that had started in the second quarter of the third century. Until the early third century all buildings in Ostia were used intensively (and as a result, stratigraphic excavations provide information about the decay only, not about the heyday of the harbour). But from then on fewer goods were and could be imported. With fewer mouths to feed in the harbours, bakeries and other commercial premises were deserted, or not used to their full capacity. The final phase was not a single moment in time. A building could still be used partly, to be deserted completely only later. And a deserted building that was not maintained anymore could still be used as a hull, a shelter, by the few remaining members of a society that did not have the means and the will to contribute to the city infrastructure and architecture.
The emergence started in the Renaissance, sparked by interest in Roman art, led by humanists. In the 19th century the scope of the study of Rome became wider, and therefore the excavations more thorough. The long final phase or process of decay was reversed by the early excavators, who cleared the debris and through restorations tried to reconstruct the situation at the beginning of the decay. What we see today, therefore, is mostly the Ostia of the second century. On closer inspection the remains of many activities in late antiquity can still be seen: thresholds that are at a surprisingly high level, blocked doors and windows, scars of walls that were removed, new walls of a much different type of masonry, and reused marble (often even funerary inscriptions and parts of sarcophagi). Only since a few decades has the research been all-inclusive: from animal bones and human skeletons to stables and sarcophagi; from modest dwellings to palaces; from shops to vast harbour basins and canals.
A photo of Ostia taken in 1855. In the background is the castle in the medieval village.
A harbour basin in Portus in the early 18th century. Volpi 1734, Tav. V.