A bold discovery surfaces from a bungled raid: a fingerprint linked to a 2,300-year-old vessel
Researchers have traced a fingerprint to a part of a vessel at the heart of an ancient crime mystery. But this isn’t a modern getaway car—it's a Scandinavian wooden plank boat, and the print dates back more than two millennia.
In a study published recently in PLOS One, scientists re-examine the cordage and waterproofing materials used to construct the Hjortspring boat, Scandinavia’s oldest known wooden plank boat. This artifact—preserved enough to recount a tale from the fourth century BCE—speaks of a failed raid against a Danish island.
“Crafted from lime wood planks bound together with cordage, the Hjortspring boat showcases the maritime technology of some of Northern Europe’s earliest seafarers,” the researchers note in their paper.
An expedition at sea
More than 2,300 years ago, a force of up to four boats attacked the Danish island of Als—and was thwarted. The island’s defenders reportedly sank the raiders’ weapons with one boat, burying the craft in a bog as an offering of thanks for victory. The discovery of the exceptionally well-preserved boat in the Hjortspring Mose bog in the 1880s preserved this story for millennia. Yet a crucial detail had faded from historical records.
“Where these sea raiders originated and why they targeted Als has long puzzled researchers,” says Mikael Fauvelle, an archaeologist at Lund University and co-author of the study.
Now, Fauvelle and his team have uncovered a remarkable clue: a fingerprint found on a fragment of the boat’s caulking material—tar used to seal the seams. While fingerprint analysis isn’t as definitive for ancient suspects as it is for modern ones, this trace powerfully humanizes the anonymous attackers who failed so long ago.
The tar clue also helps illuminate the boat’s origins. The sealant’s composition points to pine pitch, which surprised researchers and suggested origins in regions rich in pine forests. Previously, some had proposed that the raiders and their vessels came from the area around modern-day Hamburg, Germany. But the new analysis shifts the likely origin closer to the Baltic Sea’s pine-rich landscapes.
If the sea raid crews indeed sailed from Baltic coastal pine regions, they would have undertaken a long maritime voyage spanning hundreds of kilometers across open water to reach Als, underscoring the reach of these ancient seafarers. Radiocarbon dating of the lime bast cordage places the craft in the pre-Roman Iron Age, between 381 and 161 BCE.
A more definitive origin could come from tree-ring analysis, which might link the boat’s planks to specific tree sources. The researchers also hope to extract ancient DNA from the caulking tar to gain deeper insights into the people who used this boat.
The full story of the attackers remains to be written, but one thing is clear: their failed raid has carved a lasting imprint on history. As for the anonymous raiders themselves, their notoriety persists—etched into tar and timber, for millennia to come. And for us, their distant descendants, the mystery persists as an invitation to question and discuss the past.
Would you side with the prevailing origin story, or question the Baltic-born hypothesis and seek alternative explanations for these ancient raiders? What additional clues would you pursue to settle the debate about where they came from and why they attacked Als?
