In a study published last week in the Journal of Archaeological Science, a team of researchers from the University of Oslo in Norway have discovered that the Vikings distinguished among social classes, much like every other ancient society (Mayans, Aztecs, Egyptians, Mesopotamians) and that slaves who were buried with their masters were beheaded and offered as “grave gifts.”

Discovered in the 1980s by a farmer who was plowing a field, at least three of seven skeletons recovered were missing their heads. Archaeologists are suggesting that the intact skeletons represent nobles, and that any accompanying headless bodies were their servants.

While it is not uncommon to discover a tomb containing a master and the slaves they possessed while alive, Viking burials don’t always make it clear who the master is. To make those conclusions, researchers used stable isotope analyses to examine the diet and lifestyle led by the skeletons. 10 skeletons discovered in the Norwegian archaeological dig at Flakstad were analyzed, and after ruling out maternal relationships through mitochondrial DNA, they found that beheaded corpses ate like commoners while intact skeletons had an entirely different diet.

In order to gauge the dietary differences, scientists examined the ratios of certain kinds of nitrogen and carbon atoms that would accompany certain diets. While it may not be able to say what foods were the skeletons’ favorites, it can indicate that a person ate lots of land-based protein; the servant bodies were discovered to have lived on a primarily seafood diet, as was a dog who was buried at the site.

Elise Naumann, a Ph.D. student in archaeology with the University of Oslo and the leader of the research, said “These are people who had values very different from our own… There were probably a very few people who were the most privileged, and many people who suffered.”

The current theory suggests that those who ate meat and dairy were rich and powerful, or at least a kind of religious elite. Although the study sheds some light on social structures of the region, Jette Arnebourg, an official with the National Museum of Denmark, has said that the diets of the skeletons are not conclusive evidence of social status distinctions. Naumann concedes on that point, but says that they’ve proven that the people who were buried together ate vastly different foods, which if nothing else indicates that they held different standing in the community from one another.

[Image via an episode of History Channel’s Vikings on YouTube, specifically from a scene where a servant is buried at sea with her nobleman master]