Portus Claudii

About

Rome's first purpose-built imperial harbor at the Tiber mouth, begun by Claudius in 42 CE to supplement the silting river-mouth port at Ostia; two long curving moles enclosed roughly 200 ha of open water, with an artificial mole-top island carrying the Pharos at the seaward entrance. Nero completed associated works and issued sestertii celebrating the harbor's operation at its ceremonial opening in 64 CE. Exposed to open-sea swell and prone to storm damage (part of the reason Trajan later built the sheltered hexagonal basin inland of it), but the basin itself, its moles, and surrounding quays were still functioning port infrastructure in 117 CE, working alongside Trajan's newer basin. Coordinates mark the approximate center of the basin as reconstructed from excavation/LIDAR plans (Keay et al., Portus Project); exact mole outlines are better attested than this single representative point, so treat coordinates as approximate (±300 m).

What happened here

Sailing season runs roughly from spring to autumn and the port lives by it. Ships anchor in the outer basin and warp in, or are unloaded by lighters if they draw too much. Cargo comes ashore under the eye of a customs officer taking a percentage, is weighed, and goes into warehouses along the quay. Grain for Rome is the priority and everything else waits behind it. Amphorae are stacked, checked, and the broken ones dumped. Gangs of porters work by the load; shipping agents and guild offices cluster round the harbour square, advertising routes in mosaic on the floor. Divers work the bottom for dropped cargo. In winter the ships are hauled out and the whole place goes quiet.

Sources

• Suetonius, Divus Claudius 20
• Cassius Dio 60.11
• https://www.ostia-antica.org/introduction/portus-claudius.htm
• https://en.wikipedia.org/wiki/Portus
• Simon Keay, Martin Millett, Kristian Strutt, Portus: An Archaeological Survey of the Port of Imperial Rome (British School at Rome, 2005)