Brass study helps uncover close ties between Rome and Germanic Bohemia

Analysed brass objects

After analysing dozens of brass objects dating back to antiquity, a team of Czech archaeologists claims that it has proven the existence of extensive diplomatic and trade contact between the Roman Empire and the Germanic tribes that lived in Bohemia during the centuries around the birth of Christ (100 BC to 200 AD). They say that the method could also help shed light on Ancient Rome’s economy. I spoke to one of the leaders of the project, Daniel Bursák from the Archeological Institute of the Czech Academy of Sciences, and began by asking him why the team chose to focus on brass. 

“That’s the main reason why we chose to study objects found on the territory of the modern Czech Republic. We have a lot of brass items from this period located in the collections of museums and institutes. This is because of the historical situation at that time.

Daniel Bursák | Photo: Veronika Mikešová,  National Museum

“During the period that we are speaking about there was a massive influx of Roman items into the lands that make up modern Bohemia and Moravia. Back then, this area housed the Germanic Empire of Marobudos and the Romans and Germanic tribes had quite intensive diplomatic contacts at that time. We therefore had a good opportunity to analyse a lot of items that are quite rare even among those found in what were Roman provinces.”

How did you go about analysing the items?

“Because there were no other studies into the prominence of items made of Roman brass, we chose a relatively new methodology that is based on the analysis of the chemical composition and isotopic ratios.

“It is one of the first times ever that this methodology has been applied to Roman brass items and is definitely on the largest scale yet conducted.”

Preparation of the brass objects for the analysis | Photo: ARÚ AV ČR and Česká geologická služba

So where specifically did the brass found in these items come from?

“That was probably the most thrilling find we made. We now know that it most likely came from the Massif Central in central-southern France [or what was then Gaul]. It was probably was mined around the city of Lyon and the south-eastern part of the Massif Central.

“That area had recently been conquered by Ceasar, in the first century BC period that we are talking about. As we can now see, the Romans were able to collect quite a lot of potential resources from there for their economy.

“They chose brass as one of the metals for striking their coins and this territory was therefore a very useful conquest, not just as an agricultural area, but also for the mining of metals.”

So it came from what was then Gaul?


Was that the only source of brass metals for the Romans?

“What we already know from our studies is that there were definitely more metal sources for Roman brass. Literary sources, such as Pliny the Elder, mention sources in Northern Italy, in Germany and there were also some mentions of Gallic deposits used for making brass.

“However, no one knew where those sources were located and we are now much closer to finding those mines that were mentioned by Pliny the Elder.”

Brass was a much more valuable item during the time which you focused on in your study. Why?

“There are many reasons for that. First of all, brass looked more like gold than bronze did. It is more golden in colour. Literary sources also mention that even the Romans mistook brass for gold. Especially for barbarians here in the north, it must have been a very prized metal.

“It should also be stated that making brass was much more complicated than smelting copper. This is because you need to use a process called cementation. I do not want to get too much into the technical details, but you need a very specific temperature ranging between roughly 900 and 1,000 degrees Celsius and very well established protocol of how to make it. Let us not forget that this had to be carried out without any available instruments for temperature measurement.

Roman coins | Photo: Pixabay,  CC0 1.0

“Brass was therefore valued not only for its golden colour, but also for the technical complexity involved in smelting it. The Romans were able at that time to produce brass in quite substantial quantities, so much so in fact that they used it for striking quite common coins, such as sesterces. For the barbarians living north or east of the Roman borders, brass was an astonishingly attractive item.”

I imagine this would have made brass a useful diplomatic tool for the Romans then?

“It certainly must have been so. Especially in the beginning when brass started coming in and before they acquired it in substantial enough quantities. This must have been a great diplomatic tool for the Romans when dealing with these early Germanic kingdoms, such as the Empire of Marobudos.

Battle of the Teutoborg forrest | Source: Monumenta Paderbornensia 2. Ausg. 1672/Wikimedia Commons,  public domain

“The Romans, especially after they were defeated at the Battle of the Teutoborg forrest [in 9 AD during the reign of Augustus], were quite vulnerable to Germanic attacks and we see a great influx of Roman objects to these territories, including this shiny metal, after that battle. We cannot say for certain that brass was used in the form of diplomatic gifts. However, considering all of the circumstances, it would have been very useful for the Romans to use it in this way.”

Given its golden colour and attractiveness, I assume the objects found here that you analysed must have been decorative?

“Yes. These were mainly brooches and other pieces of jewellery, such as bell fittings, pins and needles.

“It should also be noted that these brass objects are quite massive. If you compare them with brooches made a hundred years before this period, they were just half their weight, so not only are they using a new method but also making much bigger decorative items.

“We sampled the items that we analysed from 14 sites, mostly from Central and Eastern Bohemia, and we found brass in almost every one of these objects. That is quite important for us, because it suggests that already at this time [1st century BC to 2nd century AD] brass could be afforded by almost anyone who was wealthy enough to possess jewellery.”

Could you tell us a bit about Bohemia during this period? Who lived here and what were their relations with Rome?

“We are talking about a period spanning 300 years and, of course, a lot of things changed during this time. At the start of that time frame, in the early 1st century BC, Celts were living in Bohemia. This civilisation ended sometime around the 30s or 40s BC.

“Around the time of the birth of Christ, specifically around 6 or 9 BC, there are historical mentions of King Marobudos migrating from somewhere in Germany to Bohemia. He was able to unite several Germanic tribes and threaten the borders of the Roman Empire which was expanding northwards.

“We need to mention that the Romans had not yet established a sophisticated web of fortresses at this time and were still consolidating their newly conquered territories in this part of Europe. Therefore, the border was more fluid and the newly conquered areas needed to be consolidated. Marobudoses Empire was therefore quite threatening to them, especially after their defeat at the Battle of Teutoborg Forrest by Germanic tribes led by another Germanic ruler - Arminius. The Romans prized Marobudos for not invading their territories after the battle.

"Sources tell us that Arminius was actually asking Marobudos to attack the Romans, but the latter refused. He was latter also referred to as a friend of the Roman Republic in Roman sources.

Arminius | Source: Wikimedia Commons

“By the 2nd century, the situation was quite different. Roman Emperor Marcus Aurelius was fighting with Germanic tribes in and around this region, defending what had by then already been firmly established Roman territories of Noricum, Panonia and Illyria. Also, the centre of Germanic power had moved from Bohemia to areas around the Danube, such as Southern Moravia, Western Slovakia, and North-Eastern Austria.

“The brass changed too. Even the Romans were not producing brass of the quality that they had been able to make during the earlier period of Augustus and Marobudos 200 years earlier. We see quite a lot of admixtures, partly due to recycling and other factors.”

I understand your research into this topic is going to continue. What specifically will you be focusing on uncovering?

“In our study, we focused on personal jewellery, which may have also been produced locally using the metal coming from the Roman Empire.

“What we are interested in now, is delving deeper into Roman artefacts, especially Roman coins. We want to see if the Romans used the same metal that they exported to the barbarians in their own coinage.

“We believe that it was the same type of brass, but there are no studies yet that prove this on such a scale. Hopefully, we will be able to answer this question in a year’s time.

“This would provide an insight not only into this region of Europe, but also towards our wider knowledge of the Roman economy as a whole.

“There are also other researchers working on this topic and we welcome this, because it could bring about discoveries of a larger scale. If we see the same results in the coinage of the metal coming from Gaul, it will underscore the importance of the newly conquered territories for the economy of the Roman Empire.”