In popular lore, few images are as synonymous with Viking brutality as the “blood eagle,” a practice that allegedly found torturers separating the victim’s ribs from their spine, pulling their bones and skin outward to form a set of “wings,” and removing their lungs from their chest cavity. The execution method shows up twice in the popular History Channel drama series “Vikings” as a ritual reserved for the protagonists’ worst enemies, Jarl Borg and King Ælla, a fictionalized counterpart to the actual Northumbrian ruler. In the video game “Assassin’s Creed: Valhalla,” Ivarr the Boneless, a character based on the Viking chieftain who invaded the British Isles in the ninth century C.E., performs the blood eagle on his nemesis, King Rhodri.

These representations take their cue from medieval sources written in both Old Norse and Latin. In each of the extant nine accounts, the victim is captured in battle and has an eagle of some sort carved into their back. Some references to the torture are terse. Others are more graphic, aligning with the extreme versions depicted in contemporary popular culture. Either way, the ritual’s appearance in these texts is intended to send a message tied to honor and revenge.

Experts have long debated whether the blood eagle was a literary trope or an actual punishment. The sources are often vague, referencing legendary figures of dubious veracity or mixing up accepted historical chronology. Unless archaeologists find a corpse bearing clear evidence of the torture, we’ll likely never know. 

If the Vikings did perform the blood eagle, does that mean the Middle Ages were as brutish, nasty and “dark” as stereotypes suggest? The answer is complex. Vikings, like many medieval people, could be spectacularly violent, but perhaps not more so than other groups across a range of time periods. The work of scholars is to understand how this violence fit into a complex society—and a new study does just that.

Set to be published in Speculum: A Journal of Medieval Studies later this month, the article sidesteps the question of whether the ritual actually took place during the Viking Age, instead asking whether the blood eagle could feasibly serve as a torture method. The answer, according to an interdisciplinary team of medical doctors, anatomists and a historian, is a resounding yes. 

Study co-authors Monte Gates and Heidi Fuller, both medical scientists at Keele University in England, were spurred to investigate the blood eagle by the “Vikings” series. The show led them to medieval sagas, which opened up further questions and made them realize they needed to consult a historian. The give-and-take nature of the pair’s collaboration with Luke John Murphy, a historian of religion at the University of Iceland, proved eminently fruitful, with the different perspectives of history and medicine pushing the scholars in unexpected ways.

“Work on the anatomical limits of the ritual spurred me to consider the wider social and cultural limits within which any historical blood eagle would have had to have taken place,” Murphy says. This, in turn, led to a more nuanced discussion of not only what could have happened, but how and why. 

In the paper, the authors move methodically through the medieval sources before discussing what would happen to the human body if the fullest version of the procedure was carried out (in short, nothing good). Unless performed very carefully, the victim would have died quickly from suffocation or blood loss; even if the ritual was conducted with care, the subject would’ve almost certainly died before the full blood eagle could be completed.