Source: Engraved in “Civitates Orbis Terrarum” (IV: Urbium praecipuarum totius mundi, liber quartus, first edition 1588)/Koeman B&H4.
The port of Ostia, located at the mouth of the river Tiber, was the main port serving Rome since its foundation and emergence as an imperial city. As the Roman Empire expanded and reached dominance around the Mediterranean, a need arose to expand the shipping capabilities and connectivity of the capital. Portus was constructed in 42 CE as an addition to Ostia, which was located just 6 km away. It represented the most important public work of the Roman Empire at that time, taking 20 years to complete, and is also known as the Claudian harbor in the name of Emperor Claudius, who initiated the project. One of the advantages of Portus was its proximity to Rome (32 km), with the construction of Via Portuensis and a canal connecting to the Tiber. Traffic between the port and Rome was so intense that Via Portuensis was expanded to become the world’s first dual carriageway.
Portus became an extensive facility covering more than 200 hectares and the most important hub of the Mediterranean for at least three centuries until the collapse of the Eastern Roman Empire in the fifth century. In 102 CE, it was expanded to include a hexagonal basin of 5 meters in depth, expanding docking space, surrounded by extensive warehousing facilities (the basin is still present today). This basin, known as the Trajan harbor, was paved at the bottom and could hold 200 ships. Portus acted as a major commercial and distribution hub and such an important facility that the modern term ‘port’ was directly derived from its name. Due to siltation and declining activity, the port facility has disappeared and is now located about 2 km inland from the sea.
In the second century, the Greek orator Aelius Aristides made the following statement concerning the prominence of Portus and the Roman trade network:
“Here is brought from every land and sea, all the crops of the seasons and the produce of each land. The arrivals and departures of the ships never stop, so that one would express admiration not only for the harbor, but even for the sea. Everything comes here, all that is produced and grows … whatever one does not see here, it is not a thing which has existed or exists.”