When a team of French and Italian archaeologists discovered the lost habour of Ostia,once ancient Rome’s primary seaport they set to work hoping that the harbour would reveal more of its secrets.
The commercial centre was founded beside the Tiber in c620 BC to give Rome an outlet to the sea and guard against enemy fleets entering the river. According to contemporary writers such as Strabo, however, Ostia was abandoned when her harbour silted up in the lst century AD, and a huge new complex was built 3km (2 miles) to the north at Portus.
While past excavations have revealed many of Ostia’s buildings and roads, the site of the harbour itself remained unknown- but now investigations led by Jean-Phillipe Goiran of France’s National Centre for Scientific Research (CNRS) have located the harbour to the north-west of the city,on the left bank of the river mouth.
With waterlogged conditions making deep excavation difficult,the team decided to extract two sediment cores which provided layers of deposits 12m (39ft) deep, Those dating to the 4th-2nd century BC were rich in grey, silty clay, pointing to a typical harbour. Anaysis of these indicated that Ostia’s harbour had once boasted a basin 65m (2l ft ) deep – the same as at Portus-thus shaking previous assumptions that this had been a shallow river port only capable of accomodating low-draft boats.
Coring operations Roman harbour city Ostia
The cores also confirmed historical accounts of Ostia’s harbour being choked with silt,showing that major floods had filled the basin with sediment in the first quarter of the lst century AD, reducing its depth to O.9m (3ft) and making navigation impossible. The harbour’s depth was an unexpected bonus’, Jean-Philippe told CWA.” we had thought that it would be at most 3-4m (l0 – l3ft ) deep, meaning that large merchant ships would have had to keep at a distance with smaller vessels bringing their cargo to the port. But now Ostia can be entered in the catagory of deep ports capable of receiving large seagoing boats.