Prelude: Trajan

During the reign of Trajan, at the turn of the century, there was a new major development. The Emperor gave orders for the digging of a second artificial harbour basin in Portus, behind the earlier basin. We have an important witness from this period: Caius Plinius Caecilius Secundus, better known as Pliny the Younger. He is famous for two letters to the historian Tacitus in which he describes details of the eruption of Mount Vesuvius in 79 AD. He owned a villa to the south of Ostia, located on the beach. Some remains in the pine forest of Castel Fusano are usually said to belong to it. In reality it was a bit further to the south, but very few remains have so far been excavated. Pliny will surely have seen the ongoing work in Portus. He was interested, because in one of his letters he gives a vivid description of the construction of moles in the harbour of Centumcellae, modern Civitavecchia.

The remains of Portus on a fresco by Ignazio Danti from 1582. The hexagonal basin was built by Trajan. Image: Testaguzza 1970.

In another letter Pliny gives a detailed description of the villa. He used to travel there from Rome on horseback. A small settlement close by provived the basic amenities, such as baths, which he used when his arrival could not be announced timely, so that his private baths had not yet been heated. Ostia provided for all other needs. Pliny must also have witnessed considerable building activity in Ostia. New baths were being erected and some large apartments of a type that would be very popular during the reign of his successor, Hadrian. In the south part of the city a large bakery emerged, opposite the theatre a warehouse. Around 112 AD the guild seat of the grain measurers was built near the Tiber. An adjacent building made up of large halls, most likely the grain weighhouse, was built simultaneously. The collegium or guild of the grain measurers had the status of corpus, body. This was an important innovation introduced by Trajan. Guilds with that status performed certain tasks in the public interest and received an exemption from some public duties in return.

But the inhabitants of Ostia were getting nervous. Portus was no longer governed by Ostia, because Trajan had made the new harbours property of the city of Rome, to which funerary fines had to be paid from now on. A wine forum, where wine was auctioned, was one of the focal points of Trajan's new harbour. So what was in store for Ostia? Would it become a sleepy seaside resort, preserving ancient memories? Or would it develop into a hub for Mediterranean trade, frequented by businessmen and Imperial officials?

Map of Ostia with buildings from the reign of Trajan (hatched).

The grain measuring centre, built during the reign of Trajan. Photo: Klaus Heese.