The Trajanic and later port – Structures and the Basin
The most enigmatic side of the whole hexagon is side VI, the site of the so-called "Imperial Palace" ("Palazzo Imperiale") (Fig. 1). This is an impressive monumental complex whose remains still stand to a height of at least two stories. Reports by 19th century archaeologists described the underground vaulted portico (cryptoporticus), colonnades, baths and possible theatre, as well as noting high quality sculptures and inscriptions. The site is of key importance since it lies in a unique position over-looking the outer basin of the Port of Claudius (Porto di Claudio) and the hexagon of the Port of Trajan (Porto di Traiano). Our work has added more detail to what is known although there is little evidence to suggest that it was a palace. The Trajanic layout of the area lying between side VII of the hexagon and the Canale di Comunicazione Trasverso is difficult to fully understand. It formed a key part of the pre-Trajanic port, and became a major focus of occupation in the late antique period, when the Basilica Portuense was constructed. All of these activities have generated a complex palimpsest of archaeological features whose geophysical signatures are difficult to disentangle and interpret. Nevertheless, it does seem that there was a large and complex rectilinear complex here into which the Basilica Portuense was later inserted.
The hexagonal basin of the Trajanic harbour was connected to the Tiber by a new canal, c. 40m wide, which joined the "Fossa Traiana" near the Episcopio and continued in a north-easterly direction to intersect with the Tiber c. 600m to the north of the "Fossa Traiana". This new canal enabled cargoes that were unloaded in the in the Port of Trajan (Porto di Traiano) to be transhipped from within the hexagon on to barges and moved towards the Tiber, and thence to Rome. All of these arrangements ensured that the whole process of transhipping cargoes and shipping them up-river to Rome would have been much more efficient in the Trajanic port than it had been earlier, a reflection of the increasing importance of Portus in supplying the city of Rome from the earlier 2nd century AD onwards.
The construction of the new Trajanic canal was central to the re-planning of the flat land lying between Portus and the Tiber. The geophysical survey has clearly revealed that a major road ran along the north side of the hexagon to the Tiber. It seems likely that this was a re-routing of the earlier Via Campana on a more direct route to Portus. Similarly, the earlier aqueduct was also re-routed to turn sharply westwards prior to the road, and then to run parallel to it in the direction of the hexagonal basin. The overall effect of canal, road and aqueduct running between the Tiber and the Port of Trajan (Porto di Traiano) must have been very dramatic to visitors approaching the port from Rome, and would have been an eloquent symbol of the imperial power represented by the port as a whole.
The site of the pre-Trajanic river port was also considerably re-developed from the Trajanic period onwards, with the appearance of a major complex of buildings close to where the road reaches the Tiber. Some of these appear to be temples within enclosures, adjacent to later mausolea. Other buildings are harder to interpret, but included warehouses.
Soprintendenza Archeologica di Ostia
One of the cemeteries associated with Portus is known to have grown up from the late 1st century AD onwards on either side of the Via Flavia some way to the south of the settlement that lies to the south of the "Fossa Traiana" on the Isola Sacra. However, our survey work has shown that much of the flat land between the hexagonal basin and the river port, to the north of the Trajanic canal was given over to burials. The large complex conventionally known as the "Tempio di Portuno" some 500m to the east of the hexagonal basin, may also have been a mausoleum (Fig. 2). All of our new evidence makes it clear that like Claudius before him, Trajan wanted to construct a monumental architectural gateway to Rome rather than just a functional harbour facility.
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