Ostia Antica was the principal port and harbor for the city of Imperial Rome. Three kilometers (2 miles) north of Ostia city, and 25 km (15.5 mi) southwest of Rome, the harbor (or Portus) was excavated into the alluvial delta of the Tiber River during the first century AD, much later than any other large Mediterranean city of its time. The city itself reached its heyday during the second century AD, with a population between 30,000 and 50,000 inhabitants, and it remained active until the third century, when it progressively declined, along with the rest the Roman Empire.
During the fourth century, the main channel of the Tiber was obstructed by sand and the port was dredged. The port of Ostia Antica was invaded, sacked and burned several times after 409 AD. The barbarian Goths captured the port in 537; nevertheless, the anchorage remained in use until the 10th century, and although to a degree silted in, the harbor basin remained in use until at least the 12th century. By the 19th century, however, all the harbor structures had been buried by alluvial deposits from the Tiber: that burial has led to the excellent preservation still visible for visitors today.
Recent archaeological excavations at Ostia have been focused on the harbor, although other studies continue on the city, including a large private home called the Domus of the Bucranium; the sanctuary of Bona Dea; and the Casa delle Ierodule, an insula in an apartment building.
Constructing Ostia Antica's Harbor
Construction began on Ostia's Harbor in 42 AD, at the behest of the Roman Emperor Claudius [ruled 41-54 AD]. Claudius built the main basin, fed by an artificial channel of the Tiber River, called Trajan's channel. The harbor and dock were completed by the Emperor Nero [ruled 54-68] in the year 64 AD, despite, according to the Roman historian Tacitus, a terrific storm that destroyed 200 ships sheltered within the harbor in 62 AD. Trajan [ruled 98–117] modified and enlarged the harbor at the start of the second century AD, adding a hexagonal-shaped basin and at least one more channel between the Tiber and Ostia.
The central collecting point of the water at Ostia Antica is the castellum aquae, which was built at the end of the first century AD. This stone tower collected the water from free-flowing canals and lead pipes, and distributed it to the harbor's residents. Water flowed to Ostia's castellum from the Malafete basin, a natural collecting point east of the town of Acilia.
Archaeology at Ostia Antica
Archaeological studies on the city itself were first instituted in the 19th century. The harbor was identified and first excavated in the 1930s: these excavations necessarily slowed during World War II, although work sponsored by Mussolini in 1938 identified the so-called "Temple of Hercules", a large Republican-period temple and sanctuary. More recent investigations have focused on the soils deposited within the harbor, with special emphasis on the environmental history recorded there. All the current work is being conducted under the administration of the Soprintendenza per i Beni Archeologici di Ostia.
The primary findings of the environmental studies confirm the historical record, identifying dredging periods and construction projects and matching historical evidence to radiocarbon dates. Pollen and ostracod (tiny shrimp) assemblages give clues to the depth of the harbor and its relative brackish nature at any one given time. For example, during the second to fourth century, the harbor depth was limited to about 1.7 m (5.6 ft).
Studies of the paintings in three buildings at Ostia have identified a technique for frescoes that significantly differs from the historically documented method written by Vitrivius. Although the method appears to have been the same as was documented by the Roman historian, the Ostia artists used local sands rather than marble fragments in the wall preparation prior to painting.
Sources
This glossary entry is a part of the About.com guide to Ruins of the Roman Empire, and the Dictionary of Archaeology.
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