Some 2,000 remarkably well-preserved bodies have stirred up creative theories about their lives. Now technology is revealing the truth about their deaths.

Tollund Man’s peaceful face hides the violent cause of his death some 2,000 years ago. A woven leather cord, also preserved by the bog, suggests he was hanged before being placed in the bog near Silkeborg, Denmark.

Marshes, mires, and swamps are murky, mysterious places found across northern Europe. A space between two worlds, a bog occurs where dry land and a body of water intersect, creating a soft, spongy terrain that is neither wholly liquid nor solid. This liminal quality may have led the early peoples of northern Europe to associate bogs with the supernatural. They were portals to other worlds, where gods and restless spirits dwelled. In more recent times, peat bogs are seen as valuable natural resources, yet they’ve retained their mystical qualities thanks to the thousands of human bodies that have emerged from their depths.

Across the ages

Around 2,000 mummified remains and skeletons have been found in

Europe’s bog bodies have fascinated people since one was first documented in 1640 in Holstein, Germany. Since then, some 2,000 more bodies have emerged in the wetlands of Ireland, the United Kingdom, Germany, the Netherlands, Poland, Scandinavia, and the Baltic States. A groundbreaking study published in January 2023 in the journal Antiquity estimates that figure is conservative, and the actual number could be much higher.

Bog bodies provide a tangible connection with a remote ancestral past, while also serving as a grim reminder of the harsh daily lives of most people. Looking at the mortal remains—whether the peaceful visage of Tollund Man or the curly hair of Bocksten Man—one cannot help but imagine their lives and ponder the causes of their deaths. Were they the most loathed among their people, or were they sacrificed to please the gods? Whether accidental drownings, executed outlaws, fallen warriors, or human sacrifices, these people’s well-preserved remains are providing fascinating windows into a 7,000-year-old tradition and the cultures who practiced it.

(Reconstructing the face of a 700-year-old murder victim.)

SWEEPING VIEWS

Tollund Man, one of the world’s most famous bog bodies, was found in a peat bog near Silkeborg, Denmark, in 1950. The body was so well preserved that his discoverers thought they had come upon a recent murder victim.ROBERT CLARK/NATIONAL GEOGRAPHIC IMAGE COLLECTIONPower of peat

Many bog bodies have disturbingly lifelike appearances thanks to a natural chemistry that prevents the decay of some human tissues. Bogs accumulate a muddy layer called peat, which is made of decaying plants and mosses. Peat has been used for centuries as fuel and fertilizer, but many peatlands are now valued for their role as highly efficient and compact carbon sinks and important parts of the fight against climate change.

Sphagnum moss contributes to the preservative powers of European bogs.AGE FOTOSTOCK

Sphagnum moss is a key component of peat and gives northern Europe’s bogs their seemingly magical preservation properties. These northern wetlands are cold, low in oxygen, and very acidic. This environment combined with antibiotic properties of the moss creates a perfect soup for preserving the human body’s calcified and keratinous structures—the bones, teeth, skin, hair, and nails. Sphagnum can leach calcium from bones, making them soft and supple. The sinuous qualities of some of the preserved bodies are because of the bones’ bending to pressure in the bog. The aquatic environment also preserves clothing made of wool or animal skin. Plant-based textiles, like linen, do not fare as well over time.

SAVING SOLES

Germany’s See Moor preserved these leather shoes from A.D. 140-380 but dissolved the bones of the man who wore them.ROBERT CLARK/NATIONAL GEOGRAPHIC IMAGE COLLECTION

The 2023 study was the first large-scale overview of well-dated human remains from these bogs and included analysis of more than 250 sites and 1,000 sets of remains. Burials were practiced as far back as 5200 B.C., but they flourished between 1000 B.C. and A.D. 1500, from the Iron Age through the Roman era to medieval times.

Assessing all these remains, the study’s authors categorized them into three groups: “bog mummies” with preserved skin, soft tissue, and hair, like the famous Tollund Man of Denmark; “bog skeletons,” whose bones are all that survived, like many of the oldest bog body finds dating back to the ninth millennium B.C.; and a third “mixed” group composed of partially mummified and skeletal remains.

Varying conditions from bog to bog across the continent created different levels of preservation. Each factor—the bog’s acidity, when a body was submerged after death, the time of year, the presence of insects, and the level of exposure over the years—contributed to a body’s condition upon its discovery and determined which parts would be preserved.

GRAUBALLE MAN’S CHANGING FATE

ROBERT CLARK/NATIONAL GEOGRAPHIC IMAGE COLLECTIONDiscovered in a bog northwest of Copenhagen in 1952, Grauballe Man, as he came to be known, is one of Europe’s most thoroughly studied bog bodies. To keep the body from decaying, conservators tanned his body for 18 months, which toughened and blackened his skin. Grauballe Man, with days-old stubble on his jaw, was in his mid-30s when he died in the late third century B.C. A large wound stretches from ear to ear across his neck. The blow cut so deep that it nicked a vertebra. A skull fracture and broken leg led his discoverers to theorize he had been tortured before death. In the 1950s x-rays were taken of the body but were very hard to read. Decades later CT scans of Grauballe Man’s remains revealed that these injuries were most likely postmortem, caused by pressure in the bog or damage during excavation. His neck wound does support him being sacrificed, perhaps to a Celtic fertility goddess after a poor harvest.Visions and revisions

Scholars had little to go on in the 19th century when they began exploring in earnest how these bodies ended up in the bogs. There are no written records documenting the rituals and beliefs of preliterate societies in the region, and early scholars pulled information wherever they could find it. Many relied heavily on the writings of Tacitus, a first century A.D. Roman historian, to inform their interpretations of the Iron Age bog sites.

Despite never having been to the northern regions himself, Tacitus wrote Germania around A.D. 98. Relying on secondhand and thirdhand sources, he described the northern peoples and their cultures. The work extols the virtues of the Germanic tribes in order to shame Romans for what Tacitus considered their extravagant behavior at home. In the section where he describes crime and punishment among the Germanic peoples, Tacitus includes approving descriptions of hanging certain criminals while drowning others in the bogs.

(Barbarians fought the Romans along the Danube for 400 years.)

Alken Enge: Military memorial1 / 3Archaeologists uncovered the remains of some 80 people at the site of Alken Enge, on the shore of Lake Mossø on Denmark’s Jutland Peninsula, where an estimated 380 bodies may still rest beneath the bog. Most of the preserved remains were young male adults who all died in a single event in the early first century A.D. Unhealed trauma wounds, as well as the presence of weapons, suggest they died in battle. Prior to this discovery, experts believed Germanic fighting forces in the area were significantly smaller, closer to 80 people rather than the hundreds buried at Alken Enge. The well-preserved bodies also reveal an interesting ritual side. Many of the human remains displayed animal gnaw marks consistent with being left exposed for up to a year before they were submerged. Other bones were found deliberately arranged in bundles. In one case fragments of hip bones from four different people were threaded on a tree branch. This evidence led researchers to suspect that time passed after the battle, and the dead lay where they fell. Survivors returned to collect the remains and deposit them in the marsh. Noting the ancient ceremonial and ritual importance of bogs and marshes across northern Europe, scholars believe this removal of war dead may likely be the victors’ attempt to memorialize their triumph. 

WARRIORS’ CEMETERY

Archaeologists uncovered the remains of some 80 people at the site of Alken Enge, on the shore of Lake Mossø on Denmark’s Jutland Peninsula, where an estimated 380 bodies may still rest beneath the bog. Most of the preserved remains were young male adults who…MADS DALEGAARD/MOESGAARD MUSEUM

This reliance on Tacitus led to colorful (and somewhat imaginative) explanations for the conditions of each body. Their grotesque limbs, often twisted, and grinning skulls, often fractured, supported the interpretation of bog bodies as disgraced people—adulterers, thieves, and outcasts—supposedly punished with first torture, then execution, and lastly submersion in the bog. Many of these explanations held for decades, inspiring poems, stories, and novels about the sad fates of Europe’s bog people.

Causes of death

Not surprisingly, bog body research has taken many different turns as technology has developed over the decades. New methods—CT scans, 3D imaging, DNA analysis, and radiocarbon dating, to name a few—are creating a larger and more complex rendering of the lives and deaths of these people. Rather than romantic stories about their deaths, scholars are finding more details, more nuance, and even more mystery.

WINDEBY I: MISTAKEN IDENTITY

In the mid-2000s, DNA analysis of the Windeby Ibog body revealed that the deceased was a teenage boy who lived around the first century A.D. His bones bore signs of poor health, either from malnutrition or chronic illness.STIFTUNG SCHLESWIG-HOLSTEINISCHE LANDESMUSEENIn 1952, workers harvesting peat in Windeby, Germany, were startled to find a body. Local archaeologists identified it as a young girl because of its slight stature and delicate features. The head appeared to be shorn and a blindfold covered the eyes. A theory formed that Windeby Girl, as she came to be called, was an adulteress. As punishment, her people shaved her head, blindfolded her, and drowned her. A male body was later discovered nearby and then interpreted as her illicit lover. This explanation held until the mid-2000s, when Heather Gill-Robinson of North Dakota State University tested the Windeby Girl’s DNA and found that she was, in fact, a he. Analysis of the remains revealed that the boy, now known as Windeby I, had been malnourished and most likely died of natural causes sometime between 41 B.C. and 118 A.D. The body showed no signs of trauma, as might be expected with an execution. The narrative fell apart further when radiocarbon dating by other scientists revealed that the supposed lover lived three centuries before Windeby I.

The 2023 study is reshaping the conversation around the ritual importance of bog bodies. Perhaps the biggest reassessment is the role of violence in each person’s death. So many of the bodies were believed to have died violently, because of the state of their corpses, but the Antiquity study could only conclusively identify the cause of death for 57 individuals: 45 died violently, six died by suicide, and four were accidental drownings.

New research has confirmed violent causes of death for some individuals like Denmark’s Tollund Man, who was hanged. Injuries on other bodies are being revealed as postmortem damage caused by pressures from the bog itself or even by accidental damage during excavation. These broken bones and fractured skulls had been seen as evidence of torture or assault. The correct identification of the cause of these injuries could feel satisfying, but it also invites more questions about the deaths.

As technology advances, scientists will be able to collect more data from these bog bodies, teasing out their centuries-old secrets. But as answers emerge, new questions are sure to follow.

TOLLUND MAN: LAST MEAL

​REST IN PEAT

When Tollund Man was discovered in 1950, Danish archaeologist P.V. Glob observed the face’s peaceful look, describing it as “a gentle expression—the eyes lightly closed, the lips softly pursed, as if in silent prayer.”ROBERT CLARK/NATIONAL GEOGRAPHIC IMAGE COLLECTIONPerhaps the most famous bog body, Tollund Man was discovered in 1950 by peat diggers in Denmark. His peaceful expression belies the presence of a leather cord around his neck that was used to strangle him around 350 B.C. Shortly after his discovery, researchers examined his digestive tract and determined that he ate about 12 to 24 hours before his death. More than 70 years later, Denmark’s Silkeborg Museum revisited the last meal in search of clues about his demise. Perhaps it would reveal new details about how he was killed. Archaeologists generally agreed that Tollund Man was a human sacrifice, but they were curious to see if any medicinal plants were consumed to ease his transition. Gut analysis revealed no such substances—just plant macrofossils, pollen, and microscopic evidence of food and drink. Before he died, Tollund Man ate slightly burned porridge with barley, flax, wild weed seeds, and some fish, indicating that he met his grim fate in full command of his senses.