Researchers have uncovered a partial human fingerprint preserved in the caulking of the Hjortspring boat, Scandinavia's oldest plank vessel, suggesting its origins along the Baltic Sea coast. The 2,400-year-old boat, used in an Iron Age raid on Denmark's Als island, was analyzed using modern scientific methods. This finding provides new clues to a century-old mystery about the vessel's builders.
The Hjortspring boat, excavated from a bog on the Danish island of Als in the early 1920s, has long intrigued historians. Believed to have been used by a group of Iron Age warriors in an attack on the island around 2,000 years ago, the vessel was sunk by local defenders as a victory offering. Weapons found with the boat were common across Northern Europe, offering little insight into the invaders' origins.
A recent study, published in PLOS One by Mikael Fauvelle of Lund University and colleagues, examined unstudied materials from the site, including cordage and waterproofing caulk. Radiocarbon dating placed the boat's construction between 381 and 161 BCE, confirming its pre-Roman Iron Age origins. Chemical analysis via gas chromatography-mass spectrometry revealed the caulk consisted of animal fat mixed with pine pitch.
Pine forests were scarce in Denmark and northern Germany during the first millennium BCE, leading researchers to propose the materials sourced from regions east along the Baltic Sea coast. This implies the boat and its crew undertook a deliberate sea crossing for the raid on Als.
Most notably, the team identified a partial fingerprint in the caulk, likely left during a repair. As the authors stated, this mark offers "a direct link to the seafarers of the ancient vessel." They added, "Finding a fingerprint on the tar fragments from the boat was a big surprise for us. Fingerprints like this one are extremely unusual for this time period."
The analysis resolves challenges from the boat's early excavation, when conservation chemicals rendered much material undateable. By locating original, untreated cordage in archives, the researchers obtained reliable dates. The study was funded by the Marcus and Amalia Wallenberg Foundation and Riksbankens Jubileumsfond, with no influence on the research process.
