Tourists travel from afar to visit the great Roman monuments built 2’000 years ago. Every day, coaches bring thousands to the best known sites: the Coliseum and the Pantheon in Rome, the Pont du Gard near Nîmes, the big Amphitheater in Pula or the Aqueduct in Segovia. They are impressive deeds of engineering indeed.
The beautiful Roman Aqueduct in Segovia in Spain
Far fewer people though visit Hadrian’s port in Fiumicino or Frejus where Augustus stationed his Mediterranean Fleet. These ports were engineering marbles which surpass anything built on land. Building ports was expensive. The engineering required the most innovative technology. We marvel about the Pantheon’s concrete dome - still the world’s largest un-reinforced dome. The same type of concrete was used to build the port of Caesarea. But on a much larger scale. 35'000 cubic meters of concrete were poured for the breakwater and port piers. 100 times more than for the Pantheon! Harbor structures were big.
Many of Caesarea's Breakwater Piers still stand today - the white foam indicates the location
In the Roman Empire, harbors were vital nods. The entire infrastructure and logistics was based on them. Ports were major trading centers, staple places for goods and locations where financial transactions were agreed. Ships were built or repaired here, they provided shelter during bad weather and Roman Legions embarked for their campaigns in these places. Without ports, Rome would not have been able to import 400’000 tons of cereals from every corner of the empire, the Roman Emperor could not have levied taxes, Roman women could not have bought the silk and cotton fabrics they loved and the 30 Legions in the provinces would remain un-supplied. All Roman Emperors invested heavily into port infrastructure.
Birdseye View of Trajan's Port built in 110 AD. It was the Empire's biggest Port.
Today, you need a trained eye to find these large structures. Over the centuries, they were battered and damaged to such an extent that they are barely visible anymore. Many silted and are now miles away from the coast (Fréjus, Rome), some were shaken by earth quakes and slipped below the water line (Pozzuoli), others succumbed to the forces of violent storms (Caesarea, Kelebris). When Rome fell in 476 AD, no ships from Egypt, the Levant, Carthage and Sicily arrived any longer. People stopped maintaining the harbors. The decay set in slowly. Romans built sturdy stuff. Over centuries though they fell apart.
In 1582, much of Rome's Imperial Port was still recognisable - Map in the Vatican Library
The most magnificent and significant port was the Portus Roman, built by the Emperors Claudius and Trajan. Ostia was Rome's oldest and served it for over 700 years. The Tiber river carries a lot of silt though. During Augustus's reign, the port in Ostia got shallower exactly when he and his successors increased the free food program. Every year, more than 1’200 grain ships arrived with their precious cargo. Given that the sailing season was limited from June to September, there were only 17 weeks to dock and unload. Grain was not the only cargo arriving. There was wine from Greece, Southern France and Spain; olive oil from Carthage, Mauritania, Spain and Asia Minor; silver from Spain; tin from England; copper from Cyprus; gold from Egypt; not to mention the luxury goods from India, China and Africa.
Sailors loading a Grain Freighter with Bags of Cereals somewhere in the Mediterranean
It is a good guess to double the number of ships arriving to 2’500 annually. This would amount to 147 ships per week. Wind and weather pattern make them arrive in clusters of course. The new harbors were built to accommodate 250 - 300 ships at the same time. The expansion started under Emperor Claudius in 42 AD - just north of the Tiber estuary. Two curved breaking piers enclosed a 150-hectare port basin. Between the two pincers, an Alexandria style light house was built on an artificial island. Sadly, little survived. It must have been impressive. The new harbor took 22 years to complete. It was inaugurated in 64 AD by Emperor Nero. Finally, Rome had a port where the biggest ships could dock (3’000 tons of cargo). It was linked by a canal to the Tiber. The whole complex was lined with warehouses, cisterns, thermal baths for the sailors and a Capitaneria. Their ruins are still visible today.
Nero celebrated the Event by Issuing this special Coin
Claudius and Nero’s project was a big boost for Rome. But the new harbor was too big. During severe storms in 62 AD, 200 grain ships were lost. Emperor Trajan added an inner, hexagonal basin for better protection and more docking space. It is still visible today, just south of Rome's international airport. He also dug a second canal (Fossa Traiana) to the Tiber. The new basin was far smaller than Claudius’ harbor but more modern and efficient. In the 2nd century AD 15’000 people worked and lived there. The harbor was renamed “Portus Romae” and declared an independent municipality in 314 AD. For anybody interested in more details, have a look at the excellent paper “Portus Augusti”.
Plan of the Ports of the Emperors (Porti Augusti)
Before the construction of Portus Rome, much smaller Ostia handled all the heavy lifting. It was complemented by the Port of Pozzuoli, a few miles west of Naples, where most of the heavy freighters docked and transferred their cargo to smaller ships. Pozzuoli was opposite Baiae, the seaside resort of the Roman elite. Augustus, Nero, Caligula and Hadrian kept villas here for the summer months. Like Ostia, the port of Pozzuoli quickly became too small.
Almost nothing indicates that Pozzuoli was once one of Rome's most important Ports
It was expanded with a large break water structure and new docking piers. Today, water breakers are solid structures. In Roman times they were often arched. Water flowed through but waves would break. This interesting concept was recently revived with “Moses”, the three barriers protecting the Venetian laguna from high waters.
Gravures of Pozzuoli from the 17th Century with the ancient Roman Breakwater still standing
Romans also built ports for their navy. The best example is Forum Julii, Frejus in France. We visited it last year. The surviving light tower now stands lost in a meadow. Unless you know that this was once the port entrance you have no idea.
The Frejus Lighthouse, La Lanterne d'Auguste, stands today in the Middle of a Field
Kelenderis was a port on the Cilician coast we visited in 2018. A splendid mosaic was discovered there in 2013. It is almost a town map for the arriving sailor. It was one of Cilicia’s finest ports and already well in use in the 4th and 5th century BC. Its position was ideal for anyone plowing the seas between the Aegean, the Levant and Cyprus. The mosaic found is priceless. It shows the harbor outline with storage facilities, tavernas and all the shops the mariners needed.
The Mosaic dates from the 5th Century AD and is a Harbor Map - Notice the Latin Sail?
Caesarea is the last port to talk about. Built by King Herod, a vassal king to the Roman Empire, it was named to please Caesar. Judea at that time had no proper harbor. Acre was in the hand of the Phoenicians. Jaffa’s harbor was tiny. The whole coast from the Nile to Haifa is one long beach. Accumulated sediments from the Nile were swept east by the sea currents for millions of years. With Caesarea, Herod wanted to put Judea on the map as major trading hub. And he succeeded. The 35’000 cubic meter of fine cement poured into cases with rocks and rubble, made extremely strong wave breakers. Many of them still stand today. Caesarea was so important that Herod built one of his three palaces there. That Apostle Paul embarked in Caesarea for his trip to Rome was not an accident but a reflection of the importance of Caesarea in the Roman trade network.
Model of the Port of Caesarea based on most recent underwater Archeology - all the Piers are artificial Structures built with Cement from the Vesuvius in Naples