When Viking soldiers sailed to England in the ninth century, some may have brought dogs and horses with them on the journey—and the creatures likely had special significance.
“They were treated more like companion animals rather than just for economic purposes,” Tessi Löffelmann, an archaeologist from Durham University and Vrije Universiteit Brussels, tells BBC News’ Georgina Rannard. “I find it really touching, and it suggests we underestimate just how important animals were to Vikings.”
In a study published Wednesday in PLOS ONE, Löffelmann and her colleagues examined cremated bone remains from a central England site called Heath Wood, the only known Viking cremation cemetery in the British Isles. To trace where the bones came from, they looked specifically at the isotope ratios of an element called strontium in the fragments.
Strontium isotopes are present in different ratios in bedrock and soils across the world, giving each location a specific chemical fingerprint, reports Kiona Smith for Inverse. This fingerprint is shared by the local plants, which live in the soil, and animals, which consume the plants (or consume the plant-eaters). Because of this, archaeologists use these isotopes to determine where ancestral humans originated and how they moved.
The team analyzed strontium isotope ratios in bones of three humans, a horse, a dog and a possible pig buried at Heath Wood. They found that all the animals and one human likely came from the region of the Baltic Shield—a piece of Earth’s crust beneath parts of modern-day Scandinavia.
Because the cremated remains of the animals were found alongside the humans, they may have been burned on the same funeral pyre, suggesting the animals held some special meaning, per BBC News. It’s also likely they belonged to a high-status Viking.
“I think this is the first time anyone has been able to prove the movement of horses and dogs with the Vikings—and likely not to be repeated soon,” Julie Bond at the University of Bradford in England who was not involved in the study, tells New Scientist’s Jeremy Hsu. “It’s such unusual circumstances, with the likelihood that these are ‘war graves’ of people and animals who died relatively soon after arrival.”
The analysis worked due to a precise series of conditions. If the animals or human had lived longer, the strontium isotope ratios in their bones might have grown to match those of the British Isles rather than the Baltic Shield. Had they been buried without cremation, the bones might have exchanged strontium with the soil, similarly affecting the isotope ratios.
This study marks the “first published strontium analysis on early medieval cremated remains from Britain,” co-author Janet Montgomery, a professor at Durham University, says in a statement. It “shows the potential that this scientific method has to shed further light on this period in history.”
The Heath Wood site is associated with the Viking Great Army, which invaded Britain in 865 C.E. While previous Viking raids had followed a “hit-and-run pattern,” per the study, this army remained longer and wintered in sites within the heart of England. Repton, a site near Heath Wood, was one of those camps, and the army stayed there over the winter of 873 to 874 C.E.
Heath Wood has a total of 59 burial mounds, and so far, only 20 have been excavated. Most of these excavations took place decades ago—in the 1940s and 50s, per the study—though some happened between 1998 and 2000. The researchers hope the other mounds hold more information about the Vikings’ animals.
“Personally, I would love if somebody would excavate maybe one or two more mounds,” Löffelmann tells Inverse. “Then I could do some more analysis and maybe see, if there are any more animals, if they came from Scandinavia as well.”