OSTIA

While the ruins of Pompeii give us an unparalleled look at a medium-sized Roman town dependent on agriculture, the remains of Ostia, the port of Rome, located at the mouth of the Tiber River, document a city of commercial importance. Like Pompeii, Ostia gives information about Roman urbanism that is unavailable from Rome itself. Unlike Rome, Ostia faded after antiquity. The neglected harbors became swampy and malarial; habitation dwindled. Sand dunes covered the Roman ruins, an excellent protecting blanket.

Ostia began ca. 350 BC as a fort (castrum), guarding access to the Tiber River and to Rome (Chapter 20). Its thick walls enclosed a rectangular area of just over 2ha (Figure 22.10). With two main streets crossing at right angles and leading to four city gates, this fortified settlement was an early example of the grid plan in Italy. During the Punic Wars, it was used as a military port.

During the second and first centuries BC, Ostia expanded beyond the walls of the original colony. To feed the large population of Rome, imported food supplies were crucial. Ostia’s harbor became a key port of entry for grain, notably from Sicily (late Republic) and Egypt (during the Empire); the grain was stored in large warehouses (horrea) in both Ostia and Rome. As a measure of the town’s growth, new walls were built ca. 80 BC, enclosing an area of 64ha. The old castrum became the forum of the enlarged town, at the crossing of the two principal roads, the cardo (north-south) and the decumanus (east-west).

The commercial importance of Ostia continued to grow, thanks especially to the intervention of the emperors Claudius and Nero. In the early empire, the mouth of the Tiber proved too small to accommodate the city’s maritime traffic. Moreover, the river and the port kept filling with silt. As a result, an artificial harbor was built 3km north of the Tiber mouth, begun during the reign of Claudius ca. AD 42 and finished under Nero. It measured ca. 1,000m across and had a lighthouse, but was not adequately protected from winds. A canal linked the port to the Tiber; modern Rome’s airport, Fiumicino, built on the site of the ancient harbor, took its name from this ancient canal. Under Trajan, ca. AD 112, a hexagonal harbor was added next to Claudius’s port. An urban center developed by these harbors. Eventually, in the late empire, the settlement, now walled, was granted status as a town separate from Ostia, with the name of Portus. But through the second century, the harbor area remained under the control of Ostia, fueling Ostia’s growing prosperity and expanding population: 50,000-60,000, according to one estimate (Meiggs 1973), but only 22,000, according to another (Storey 1997).