Sunday, January 23, 2011

A land of watchtowers – New research sheds light on Roman occupation of Portugal

This hilltop watchtower is one of 24 that were built in the Alto Alentejo region
of Portugal during a period of Roman occupation. In this picture
Rui Clemente, one of the team members, takes measurements.
Photo courtesy Joey Williams.

 A view of the countryside to the west of the watchtower. Photo courtesy
Joey Williams.

The archaeological team at work digging up the watchtower. Photo
courtesy Joey Williams

A team of archaeologists, working in Portugal, are exploring a system of 24 hilltop watchtowers set up in the aftermath of a Roman civil war.
“You have a rebellion put down and a landscape pacified and reorganized and you have these towers suddenly appearing,” said Joey Williams, of the University at Buffalo, who is co-leading the project along with archaeologist Rui Mataloto of the Câmara Municipal de Redondo.
The team’s work began 10 years ago when Mataloto surveyed the watchtowers, recording their features and investigating the artefacts found on the surface. Later he teamed up with Williams to excavate one of them, a 9 x 5 metre tower named Caladinho. The team’s preliminary results were presented recently at the annual meeting of the Archaeological Institute of America.
Civil War
Williams said that the civil war that preceded the tower building was a nasty one. “In this region between 82 BC and 70 BC there was a breakaway Roman Republic where a Roman statesman Quintus Sertorius mutinied,” he said. “He goes to Iberia and he brings a bunch of dissatisfied Romans with him.”
They created a shadow Roman senate and challenged Sulla, the dictator of Rome, for control of the area.
At first the rebels beat off Rome’s forces, inflicting heavy casualties. Pompey, the famous Roman general who was later defeated by Caesar, reportedly lost 10,000 men in a single battle. However he didn’t give up, eventually being reinforced with more troops and supplies.
Meanwhile Sertorius, despite his military victories, faced dissention from within. “In the midst of the campaigning season, his Italian officers, led by Perperna, turned against him. Inviting him to a banquet, they treacherously murdered him,” writes historian Leonard Curchin in his book on Roman Spain.
With the death of Sertorius, the rebellion waned, and in 61 BC a new Roman governor named Julius Caesar took over the region.
“Seeking both military glory to further his career and booty to repay his creditors, he raised a third legion and launched a lightning campaign against the Lusitani and Callaeci (tribal groups in the area),” writes Curchin.
Caesar was ruthless, “plundering even those towns that opened their gates to him.”
Along the watchtowers
The 24 watchtowers, possibly anchored by a larger fort at a site called Castelo da Lousa, were set up at some point in the mid 1st century BC, roughly the time when the civil war ended and Caesar’s period of governance began. They are located in Alto Alentejo, a region right in the center of modern day Portugal.
There would have been no easy way for the towers to communicate with each other. “This is not a network, they don’t have intervisibility, they can’t signal each other,” said Williams. “They can’t light a lantern or wave a flag at each other.”
This means that the occupants of the towers were not interested in controlling a wide area, but rather “they’re only concerned with their local landscapes.”
Many of the towers contain slag, evidence that they were involved in mining operations, possibly run by convicts or slaves. Williams pointed out that recent archaeological work in Jordan has revealed that watchtowers there were set-up to survey slave-mining operations.  “We may have a similar situation to what’s in Jordan,” he said.
Digging up Caladinho
Caladinho, the tower the team is in the process of excavating, is located on top of a ridge and overlooks plains to the north and west. To function effectively as a watchtower it would have been at least four meters tall as there is a rock outcrop that size right beside it. 
To the west of the tower the team discovered the remains of a wall. It was one meter thick by two meters tall. “It is a very substantial wall, and it does a very Roman thing where it incorporates defensive aspects of the landscape that are already present,” said Williams.  He said that more work needs to be done to determine if it surrounds the watchtower.
When the team dug into the tower itself they determined that it has two main rooms, a large one in the southwest and a narrow one in the northeast. These are connected by an L-shaped corridor.
As work continued on the tower the team found examples of an artefact not generally associated with Roman soldiers – loom weights, used for weaving – 52 of them in total. This suggests that Caladinho was used for much more than military surveillance. “The sustained domestic activity suggested by the loom weights runs counter to our interpretation of the site as a watchtower,” wrote Williams and Mataloto in the paper they presented.
It also left the team with a question, why would Roman soldiers be doing so much weaving?
There are many possibilities. The simplest explanation is that the Romans had a lot of clothes to make and repair. “Roman inscriptions tell us that the people who made clothing weren’t always women,” said Williams.
He added that the Roman army had to be largely self-sufficient while working in the field, “you would have to have someone also who would repair clothing.” That job may have fallen to those who garrisoned this watchtower.
Another possibility, and one the team plans to investigate further, is that the inhabitants of this tower were not Roman soldiers but were in fact civilians living in a fortified location.
Regardless of who was living here they certainly liked pottery. The team found the remains of terra sigillata, a type of fine ware. One of the pieces has the name of A. Vibius Scrofula, a name commonly seen on pottery produced in Arezzo between 40 – 15 BC. More examples bear a stamp with the name DAR or EVS DAREVS, this means that they were probably produced by the potter Dareus who was active in Lyon between 30 – 20 BC.
“Whomever’s living here had some nice dishes,” Williams said.
As the team excavated they also uncovered the remains of a smelting furnace. It would have been installed by someone after the tower was abandoned. “After the tower had begun to collapse some squatters came and used the structure as a support for their furnace,” said Williams.
The team also found plenty of slag at the site and more work needs to be done to determine if mining was also going on at the time the tower was occupied.
Exploring a Roman Villa
The team also took time to survey a nearby Roman villa, located just down the slope. “Around the time the fort is falling out of use, this villa down the slope is founded and grows quite large,” said Williams.
The team found a massive amount of slag, so much that the team leaders asked people to stop collecting examples after just 15 minutes of survey. They also found ceramic, brick, tile, window glass, column bases and even a bit of statuary.
Williams believes that this slag may be the key to understanding what was going on at these watchtowers. As mentioned earlier most of the other towers have large amounts of this material. It’s possible that they were involved in mining operations and, with the local inhabitants not being very friendly, the Romans chose to base these mining operations in hill top watchtowers.
Then, as time went by, and the region was pacified, the Romans left the towers and set up operations in nice villas. “It may be that the inhabitants of this tower got rich from their industry and built this villa down the slope,” said Williams.
It’s a hypothesis, one of several that could be made. It’s something for the team to think about as the winter goes by and summer, and the next field season approaches.


  1. VERY cool....I love those old fortesses / Watchtowers on Spain's coast as well...

  2. In ancient and historic times, smelting of metals, which produces slag as a waste product, normally took place in close proximity to the mines from which ore was extracted.

    It is curious that there is no mention in this article of ancient mines in the vicinity of those "watchtowers" where slag was found.

  3. Thanks for your comment Dan, in all likelihood there is a mine nearby however more research needs to be done to determine exactly where it is.

    1. Was the origin of the slag ever found?


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