One of the many mysteries surrounding the topography of ancient Rome and its ports has been the location of the navalia – the military shipsheds housing the galleys that served the city during its expansion across the Mediterranean and that safeguarded the arrival of its food supplies under the empire.
Classical sources indicate they were located in Rome during the Republic. One recent study suggests that they should be identified with the massive building known as Porticus Aemilia down on the banks of the Tiber in the emporium quarter. If so, it is clear that at some point in the early Imperial period, the building could have no longer housed ships. But there was still a need for some kind of seaborne military presence close to Rome to ensure the safe passage of food supplies to the capital. This must have been guaranteed by ships periodically repaired and sheltered in navaliae at Ostia, Portus, or Centumcellae (Civitavecchia), as well as the long-stop of the Roman fleet-base at Misenum on the Bay of Naples.
Recent work has identified a possible navalia at Ostia; but its Imperial connections, the capacity of its infrastructure, and the importance of the cargoes unloaded there must make Portus the most obvious choice.
Establishing the navalia
The navalia is part of a complex of important buildings located on an isthmus of land between the great Claudian and Trajanic basins at the heart of the port. One of these is the Palazzo Imperiale, a major administrative complex surrounded by water on three sides that stood three storeys tall and was lavishly decorated with colonnades, mosaics, wall-paintings, and sculptures. Excavations in spring 2011 concentrated on defining the south-eastern façade of the building, thus making it possible to gain a better understanding of its architectural scheme.
The navalia lies about 25m to the east of this façade of the Palazzo Imperiale, and enjoyed rapid access to the Claudian basin to the north and the Trajanic basin to the south. Its remains were first recorded by Rodolfo Lanciani in his 1865 account of the clearance of this part of the site by Alessandro Torlonia, and his interpretative plan indicates that he thought they were grain warehouses (magazzini annonarie); they were looked at again in the 1930s by Giuseppe Lugli who was more circumspect, and in his published plan he referred to them simply as warehouses (magazzini). Part of the difficulty in understanding this site is the fact that it covers a huge area, is heavily obscured by trees and other kinds of vegetation, has been heavily landscaped in recent years, and has a deep structural sequence about 3m down.
The building is rectangular: it runs about 160m from east to west, measures 58m north to south, and was open at both ends. Its northern façade lies about 30m to the south of the Claudian basin edge, part of which was excavated by the team in 2007. It has a complex vertical stratigraphy incorporating at least three major structural phases. In the earliest of these, which corresponds to the Trajanic phase, there is clear evidence for a westerly corridor about 5m wide, followed by a series of at least eight bays 12m wide by 58m long. These are defined by a series of massive brick-faced opus caementicium piers, some of which still stand to a height of around 5m.
This is an extract. The full article can be found in issue 51 of Current World Archaeology, on sale now.