HARBOUR, TRAJAN, AE Sestertius (Portus Trajani)

Portus Trajani
Æ Sestertius (26.66g, Ø35mm, 6h). Rome mint. Struck AD 104-111.
Obv.: IMP CAES NERVAE TRAIANO AVG GER DAC P M TR P COS V P P laureate draped bust of Trajan facing right.
Rev.: (PORTVM TRAIANI around, S C in ex.), Basin of Trajan's harbour (Portus Traiani), near Ostia, surrounded by warehouses, ships in centre.
RIC 471 (R2); Cohen 305; BMC 770A; Foss (Roman Historical Coins) 104:59
ex Jean Elsen Auction 95; ex coll. A. Senden: "L'architecture des monnaies Romaines".

Due to the vulnarability of Portus Claudii, witness the events of 62 AD when a violent storm destroyed some 200 ships in the port, Trajan built a second one farther inland behind the port of Claudius. The work was carried out in the years 100-112 AD, and included improvements of the Claudian harbour. It was a hexagonal basin enclosing an area of 39 hectares, and communicating by canals with the harbour of Claudius, with the Tiber directly, and with the sea. The capacity of the harbour was much enlarged, and many new warehouses were built around it, remains of which may still be seen: The fineness of the brickwork of which they are built is remarkable. The sides of the hexagonal basin were over 350 m, the maximum diameter more than 700 m., and 5m deep. The bottom was covered with stones, at the north end gradually sloping upwards, to reach a depth of only one meter at the edge of the basin.

The basin could contain more than 100 ships that did not moor alongside the quays, but at a straight angle. It was surrounded by a few wide treads (total width c. 6 m.). On the quays was a wall, with five narrow doorways (1.80) on each side of the hexagon. The doorways are too narrow for wagons. Apparently the goods were unloaded and carried by slaves. This can also be seen on several reliefs and mosaics. The wall facilitated the control of the flow of goods, for the Customs Service and the levying of import duties (the portorium).

The hexagon may have been designed by Apollodorus of Damascus, the architect of Trajan's Market in Rome. No other harbours are known with this shape, suggesting that it was chosen not only for practical purposes, but also for aesthetic reasons.

Portus was the main port of ancient Rome for more than 500 years and provided a conduit for everything from glass, ceramics, marble and slaves to wild animals caught in Africa and shipped to Rome for spectacles in the Colosseum.