Parts of pelvic bones belonging to four different Germanic warriors were found threaded on a stick as a post-battle ritual act at Alken Enge, Denmark.

Animation: Peter Jensen, Archaeological IT, Aarhus University and Moesgaard Museum.

Archaeologists working in a sprawling wetland in Denmark have uncovered 2,000-year-old human remains that are challenging traditional ideas about "barbarian" warfare in northern Europe. The research, which was published today in the journal Proceedings of the National Academy of Sciences, also provides a unique look at how Germanic tribes memorialized their battles.

What the team found:

Archaeologists excavated 2,095 human bones and bone fragments—comprising the remains of at least 82 people—across 185 acres of wetland at the site of Alken Enge, on the shore of Lake Mossø on Denmark's Jutland Peninsula. Scientific studies indicate that most of the individuals were young male adults, and they all died in a single event in the early first century A.D. Unhealed trauma wounds on the remains, as well as finds of weapons, suggest that the individuals died in battle.

The team didn’t dig up the entire 185 acres, but the researchers extrapolated that more than 380 people may have been interred in boggy waters along the lakeshore some 2,000 years ago, based on the distribution of the remains that were excavated.

Why is this discovery so important?

The find significantly increases the estimated size of armies in Iron Age Europe.

Despite all of the accounts from Roman writers about the "wild and savage" "barbarians" of Germania, we know very little about the battle capability of Germanic tribes. The few known battle sites in Germany itself (most notably centered around the Battle of the Teutoburg Forest) contain very little in the way of well-preserved remains, and questions abound about how large “barbarian” armies actually were and how they were organized.

View Images The violent nature of Germanic tribes was a popular theme in ancient Roman art and literature. This Roman sarcophagus depicts a battle between Imperial troops and 'barbarian' warriors in the late second century A.D. Photograph by DEA, A. DAGLI ORTI

An army of several hundred people far exceeds the population scale of Iron Age villages in the region, the new paper notes, suggesting that a war band of this many men required the right kinds of organization and leadership skills to recruit fighters from far distances.

Princeton University archaeologist and Barbarians author Peter Bogucki (who did not take part in the study) notes that, until now, the working size for martial bands in Iron Age south Scandinavia was roughly 80 individuals, an estimate based on ritually sacrificed weapons discovered at Hjortspring that would support a band of that size.

"If the [paper's] estimates are correct," Bogucki says, "these armies may have been several times larger."

Why would people be fighting in a marsh? That doesn't sound ideal.

Here's where it gets really interesting: Many of the human remains show animal gnaw marks consistent with bodies left exposed somewhere else for six months to a year before being submerged in the wetland. Others bones are deliberately arranged in bundles with stones brought in from other areas, and in one case, fragments of hip bones from four different individuals were threaded on a tree branch.

This leads researchers to suspect that after a period of time, the remains were collected from an yet-to-be discovered battlefield and ritually deposited in the marsh. However, the southern areas of the site also revealed many very small bones, which could easily be overlooked when gathering skeletonized remains. This may indicate archaeologists "could actually be very close to the actual battle site," says study coauthor Mads Kähler Holst, an archaeologist at Aarhus University and executive director of the Mosegaard Museum.

Noting the millennia-long ceremonial and ritual importance of bogs and shallow lakes across northern Europe, Bogucki believes the removal of bodies from the battlefield after a period of time and their interment in the marsh may likely be the action of the victors trying to memorialize their triumph.

View Images Adult leg bones were gathered from the battlefield and arranged in the wetlands along with non-local stones. Photograph by PNAS

"This is 'memory work' after the battle," Bogucki explains. "They are deliberately trying to create some collective memory of the event."

So who was battling who?

Although they battled Germanic tribes across much of Europe in the first century A.D., Roman armies never made it as far north as southern Scandinavia, and the team didn’t find evidence for direct Roman involvement in this battle.

"The trauma [on the bodies] is also consistent with what we would expect from an encounter with a well-equipped Germanic army," adds Holst.

Bogucki agrees: "This was barbarian-on-barbarian," he says, noting that the military organization and scale of the conflict between Germanic armies some 2,000 years ago in Denmark wasn't necessarily motivated or influenced by contemporary Roman incursions into barbarian areas south of Scandinavia.