About 6,200 years ago, a group of at least 41 men, women and children were brutally murdered before being dumped in a mass grave in what is now Eastern Croatia. Initially, the archaeologists who uncovered the tomb in 2007 wondered if the victims were an entire interconnected community targeted for execution. But a new analysis reported in the journal PLOS ONE– including what is the largest genetic study of an ancient massacre to date – reveals that the victims were mostly unrelated. This startling discovery raises more questions than it answers: most importantly, why were these individuals murdered and who killed them?
“That’s the million dollar question,” said study lead author Mario Novak, an archaeologist at the Institute for Anthropological Research in Zagreb, Croatia. “We just don’t know.” And unless clear archaeological evidence is found nearby, he adds, “I don’t think we’ll ever find out.”
Dig under the garage
The old massacre site was accidentally discovered during the construction of a garage in the Croatian village of Potočani. The burial pit – six feet wide and three feet deep – contained the skeletal remains of at least 41 people, some still articulated, some broken to pieces.
Archaeologists from the University of Zagreb archaeological team who happened to be in the area at the time were called in and assumed the remains belonged to victims of modern warfare, perhaps from World War II or the Balkan conflict in the nineties. But an initial investigation revealed no bullets or uniforms, and teeth showed no evidence of modern fillings.
Additional excavations uncovered fragments of ancient pottery, and radiocarbon dating of three human bones revealed the site to be 6,200 years old. Based on the date and location and the type of pottery found, researchers concluded that the victims belonged to the Lasinja culture.
Very little is known about these peoples, says Novak, and only one other cemetery in Croatia related to the Lasinja culture has been excavated. “This is one of the least studied prehistoric cultural complexes in the region,” he says. Prior work on that other cemetery suggests that it was herders who moved their livestock to different grazing areas depending on the season. They also mined copper to make tools.
Bioarchological research identified 21 men and 20 women, including adults as young as 50 years old, adolescents and children as young as two years old. It quickly became apparent that they were not dying of anything approaching natural causes.
Three adult males, four adult females and six children were found with damage to the sides or back of their skull. These fatal injuries – fractures, stab and piercing wounds and cuts – were done with weapons or tools, perhaps stone axes and clubs or metal instruments. The murder weapons were not found at the site, but it appears that these injuries were inflicted in a single event in time.
Especially grim was the fact that some skulls showed multiple injuries. “One hit was enough for most people,” says Novak. “But we have two or three people with four skull injuries. This was some kind of exaggeration or frenzy. “
A History of Violence
What was clear, however, is that this massacre was not the result of warfare: mass graves resulting from combat usually show mostly adolescent or adult men, not women and children. There were also no injuries to the faces or wounds on the victims’ forearms, which happen when people instinctively raise their arms to block incoming attacks. These people were likely immobilized, perhaps squatting or kneeling, with their hands tied.
“They didn’t defend themselves,” says Novak. “I would say this was a pre-planned mass execution.”
The Potočani massacre isn’t the first to have been found from European prehistory – another mass grave from a little further back in time in Halberstadt, Germany, for example, is filled with victims killed by targeted blows to the back of the head.
“The cranial injuries look like other massacres I’ve worked on – very similar in location and age range, unfortunately,” said Trish Biers, an osteologist and paleopathologist at the University of Cambridge who was not involved in the work. .
Hoping to learn more about the victims of Potočani, the investigation team extracted the DNA of 38 individuals from the site. The results showed that they all had the same genetic ancestry: along with a small number of ancestors from hunter-gatherer societies in Western Europe, the predecessors of these people came from Anatolia, which is now much of Turkey. They originally brought agriculture to Europe some 8,500 years ago. A few millennia later, some of their descendants roamed the Balkans with their livestock.
While some of the dead were closely related – for example, the DNA analysis identified a man, his two daughters, and his cousin – 70 percent of the individuals were not. One possible implication is that these victims were part of a larger community made up of many families.
The ghost threat
Biers says her work on archaeological sites in both North and South America shows that people who were not necessarily closely related at the genetic level had social kinship groups determined by their occupation, such as fishermen, farmers, or artisans.
However, social kinship is something “that we can’t tell from genetics,” said Christiana Scheib, an archaeologist specializing in ancient DNA at the University of Cambridge who was not involved in the work. Ideally, non-massacre graves from the area would paint a picture of what the normal distribution of the dead would have been, both genetically and in terms of kinship groups. But so far the mass grave of Potočani stands alone; no adjacent settlement has been found.
Adding to the mystery is that nothing at all is known about the killers themselves. “We have no traces of the people who committed this atrocity,” said Novak. The perpetrators may have belonged to a rival group, from elsewhere or closer to home. The killers may even have come from the same population as the victims.
It is also impossible to speculate on a motif. Other massacres and episodes of mass violence from European prehistory have been attributed to antagonistic factors such as xenophobia or climate change, when drought caused resource shortages and subsequent violence. But at Potočani “we have no indication whatsoever of climate change during this period,” says Novak.
All that’s abundantly clear is that this fundamentally dark human behavior has continued for millennia. Mass killings have taken place all over the world for at least 13,000 years. While legal systems were eventually introduced and society in general became more orderly and less violent, mass killings on a large scale became easier over time. The ax was replaced by the rifle; warring tribes were replaced by state-sponsored genocide.
If sites like the one in Potočani tell us anything, “it’s that people haven’t changed in the last 10,000 years,” Novak says. “If they’ve done that, they’ve gotten worse.”