Bold truth: a 2,300-year-old fingerprint on a pine tar fragment reveals more about an ancient failed raid than any artifact alone ever could.
A team of researchers has re-examined the cordage and waterproofing used to construct Hjortspring, Scandinavia’s oldest wooden plank boat, turning a forgotten relic into a surprising storyteller about early Northern European seafaring. Their study, published in PLOS One, expands our picture of a mysterious assault on a Danish island in the fourth century BCE and the boat that carried the attackers.
The Hjortspring boat, built from lime wood planks and fastened with rope, embodies the maritime know-how of Northern Europe’s earliest seafarers, the researchers note. About 2,300 years ago, up to four boats descended on the Danish island of Als, yet the raid failed. Danish defenders reportedly sank the attackers’ vessel in a bog and kept their weapons as spoils of victory—a tale that would have faded into legend were it not for a remarkable preservation in Hjortsborg Mose, where the boat was unearthed in the 1880s.
Still, one pivotal question remained unresolved: where did these sea raiders come from, and why Als? As archaeologist Mikael Fauvelle of Lund University explains, the latest analysis provides a direct, if fragile, breadcrumb—a fingerprint impressed on the caulking material, tar, used to keep the boat watertight.
Though fingerprint analysis has limited power when applied to ancient crime beyond our modern capabilities, this tiny mark underscores a shared humanity across the ages: the same impulse to raid, defend, and leave a trace persists through time.
The tar itself adds a geographic clue. The researchers report that the Hjortspring boat was waterproofed with pine pitch, a detail that points to a region rich in pine forests. Previously, some scholars proposed a source near today’s Hamburg area in northern Germany, but Fauvelle and colleagues now lean toward a Baltic Sea provenance. If accurate, the raiders crossed hundreds of kilometers of open sea to reach Als, highlighting a long-distance maritime capability in this era.
For dating, the team carbon-dated the lime bast cordage from the boat to roughly 381–161 BCE, placing it squarely in the pre-Roman Iron Age.
Future work could pin down the origin even more firmly. Tree-ring analysis might link individual planks to specific forests, and researchers hope to extract ancient DNA from the caulking tar to gain deeper insights into the people who used the boat. Such advances could transform a partial mystery into a clearer chapter of early Nordic seafaring.
As we wait for the next discoveries, the attackers’ anonymity endures in legend and in the surviving plank. They may have hoped to vanish from history; instead, they’ve now sparked a conversation that connects us to a distant moment when a botched raid still speaks loudly about who we are today.
