When a family cutting peat for fuel unearthed a mysterious body in a Danish bog in 1950, they ᴀssumed the well-preserved corpse was a local murderer’s latest victim. In fact, he was anything but: Although the man had been killed, his body dated from the Iron Age about 2,400 years ago.

Now known only as the Tollund Man, his incredibly preserved face, stubbled and slightly smiling, has ensured him a place as one of the world’s most famous bog bodies—made even more mysterious by the fact he was the ᴀssumed victim of human sacrifice.

In the decades since his discovery, scientists have studied Tollund Man extensively and pieced together more details about his life and death. Here’s what to know about the naturally mummified man.

Who was Tollund Man?

The presence of wisdom teeth suggest the Tollund Man was at least 20 years old when he died in Denmark’s Bjældskovdal bog in Jutland, but researchers think he was actually between 30 and 40. Radiocarbon dating indicates he died at some point between 405 and 380 B.C.

(We thought we knew the secrets of Europe’s bog bodies. We didn’t.)

Standing at about 5 foot 3 inches, the Tollund Man was discovered in a sleeping position with a rope around his neck. An autopsy revealed he had died of hanging, noting his extremely well preserved head and face.

After his death, the acidity in the peat bog preserved Tollund Man’s bones and many of his soft tissues, including an intact yet shrunken brain and intestines complete with their contents. Tollund Man’s skin and nails had cured and blackened over thousands of years spent in the oxygen-free environment of the bog. But their full decomposition was blocked by the chemicals that are produced when sphagnum moss, the main moss that comprises peat, degrades.

Today, his body is preserved at the Silkeborg Museum, a Danish cultural heritage museum near the place of his discovery.

Who were his people?

Tollund Man lived during the early part of the Iron Age in the years before Rome conquered the majority of Europe. During the period, Jutland was well populated and home to villages and farms. The era’s farmers grew grain, kept animals, and engaged in religious rituals that involved leaving sacrifices—often food or weapons, but sometimes human bodies—in the local bogs.

Modern-day researchers suspect these bogs were seen as supernatural sites with connections to the gods and the afterlife. But since the Jutland dwellers left no writing behind, it’s unclear what actually drove their religious rituals.

(This ancient society tried to stop El Niño—with child sacrifice.)

What he wore

Bogs are famous for preserving clothing along with bodies, like the knitted clothing that surrounded a Scottish bog body found in 1951. But Tolland man wore much less apparel: He was buried naked, clad only in a cap and belt.

Further investigations have revealed that Tollund Man likely wore shoes for part of the year, but also walked barefoot much of the time. Stubble on his face indicates he must have shaved.

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

But though he was clearly killed on purpose, Tollund Man’s body was also carefully buried, and his mouth and eyes closed. Ultimately, that careful burial, his hanging, and the fact that cremation and grave burials were more common at the time than throwing bodies into bogs is why many researchers do believe his death was part of some kind of sacred sacrifice.

His remaining mysteries

Though it’s been nearly 75 years since his discovery, Tollund Man could continue to yield more information to curious archaeologists. During scientists’ initial experiments with the bog body, his head was carefully preserved and was put on display in Denmark. But his body dried out and was misplaced—yes, misplaced.

For decades no one knew where the bog body’s limbs and organs were. This led to a bizarre treasure hunt in the 1980s, when researchers armed with new technologies realized the potential worth of the rest of the body and asked for the public’s help locating the remainder of the corpse.

(Ötzi the Iceman: What we know 3 decades after his discovery.)

It turned out that the severed parts had been housed at a variety of museums and insтιтutions throughout Denmark. The hunt yielded everything except for the internal organs and the bog body’s right big toe, whose location remained a mystery until the children of the former conservator returned it to the museum after their father’s death.

“Now nearly all body parts are in the museum[’]s possession,” the Silkeborg Museum says on its website. “Should anyone, however, come across a mysterious jar containing what might [be] his internal organs, we would be most interested to hear from you.”

These remains could still produce more insights, though researchers have so far been unsuccessful at obtaining ancient DNA from Tollund Man’s tissues.

In the meantime, the bog man has inspired everything from poems to music to children’s books—a testament to the ongoing fascination he invokes in both scientists and the public. “He is not merely a museum piece, but a man,” one archaeologist told The Age in 1956. “We refuse to believe in his death. There is a living man behind the warmth and fine humor of his face.”