Everyone knows the Romans were highly-skilled engineers. But not many people realise one of their most impressive engineering feats is located in Shushtar, Iran, deep in the homeland of their mortal enemies: the Persians.
How did this come to be?
The defeat of Emperor Valerian
Emperor Valerian, also known as Valerian the Elder (he was already in his fifties when he became emperor), ruled Rome from 253 to 260 CE. This was a pretty rough time for the Roman Empire. Goths were attacking the empire in Asia Minor, the Persians were looting their cities in Armenia and Syria, and plague was ravaging them at home in Europe.
In 260 CE Valerian took his army east to do battle with Shapur I, the Persian emperor. The battle took place in Edessa in Upper Mesopotamia (now Anatolia in southeast Turkey).
Valerian was thoroughly defeated, and became the first Roman emperor to be captured as a prisoner of war. The capture of Emperor Valerian is immortalised in the Triumph of Shapur I inscription at Naqsh-e Rustam.
The Historic Hydraulic System of Shushtar
It wasn’t just Emperor Valerian who was captured; it was his whole army of 70,000 men. Also captured, and enslaved, was the famous Roman engineering corps.
Shapur suddenly found himself in control of quite a lot of Roman slaves.
What did he do with them all? He put them to work.
Who were the Roman engineering corps?
The Roman engineering corps were a class of troops that accompanied the armies on their manoeuvres but were exempt from fighting. Their task was to build temporary camps for the army when they were mobile, to fortify the camps when they were stationary, to build bridges and roads behind the army to ensure communication with the empire (and requests for reinforcements) could be achieved as quickly as possible. They also assisted in siege warfare, they built aqueducts for town water supply, they excavated canals and irrigation channels, and generally helped out wherever they could.
While their primary objective was usually just the erection of a functioning structure, with no thought to its form, there were times when bridges and aqueducts and town fortifications were made unnecessarily pleasing to the eye. This was done to demonstrate the Roman Empire’s might and superiority, and impress (and hopefully subdue) the people they were conquering.
Band-e Kaiser (Caesar’s Dam), also known as the Bridge of Valerian, is the easternmost bridge built by a Roman force (even though in this case it was a Roman slave force who built it). The hybrid bridge-dam was 500 metres long, had 45 arches, and was the first of its kind in Persia.
It remained in working condition until the late 19th Century, but, as you can see in the photo above, it is currently in a state of disrepair.
The two dam-bridges of Band-e Kaiser and Band-e Mizan worked together to raise the water level of the Karun River by several metres. Band-e Mizan also diverted river water into Gargar Canal, where it was used to operate Shushtar’s hydraulic system.
The water mills
The river water flowing down Gargar Canal was split into a network of smaller canals, and funnelled underground to the water mills site. Water from this basin was also used to irrigate orchards and agricultural crops downstream.
It’s thought that there were once up to 50 water mills in operation here, each working as a primitive source of power; their main function to crush grains. The UNESCO listing for the Shushtar Hydraulic System describes the site as a masterpiece of creative genius.
Were all those aesthetically-pleasing cascades essential to the operation of the water mills? No, they were not. They were just a little flourish the engineers snuck into the design to jazz it up a notch.
The way I see it, those Roman engineers, after being captured and told that they must design and build the Shushtar Hydraulic System, had two options before them:
1) do a lousy job and pretend that that was the best they could do. I’m guessing they could have gotten away with this option as the slave-masters who were supervising them wouldn’t have known any better. Also, they were mortal enemies, and the Persians had enslaved by them. Why would they go out of their way to help their enemies? Doesn’t make sense.
2) do a job that they were proud of, and that would still be functioning a thousand years after the Sasanian Empire (i.e. Shapur’s Empire) had ceased to exist.
They went for option two. That’s engineers for you.
Shushtar is located in Khuzestan province in western Iran, about 80 kilometres from the Iraq border. There are no direct buses to Shushtar from anywhere useful. If you’re coming from Shiraz then you’ll have to change buses at Ahvaz. If you’re coming from Tehran or Kermanshah then you’ll have to change buses at Dezful.