Who built Scandinavia’s oldest wooden plank boat? An ancient fingerprint offers clues.
Archaeologists examining an ancient boat discovered in Denmark more than a century ago are getting help from a clue usually associated with crime scenes. A human footprint left on the Hjortspring boat allows archaeologists to determine which ancient European group sailed the 2,400-year-old boat. The results are detailed in a study published today in the journal PLOS Oneand help scientists understand where the shipbuilders of the oldest plank ship in Northern Europe are located maybe came from.
“Finding a fingerprint on the ship’s tar fragments was a big surprise for us. Fingerprints like this are extremely unusual for this period,” the study authors wrote in a statement.
Fauvelle et al., 2025, PLOS One.
What is the Hjortspring Boat?
The Hjortspring ship is considered the oldest known plank ship in Northern Europe. Measuring approximately 65 feet long and weighing more than 1,000 pounds, it could carry 24 people with their weapons and other equipment. Builders used basswood to add flexibility to the boat and made the paddles from maples. According to the National Museum of Denmark, the Hjortspring boat is evidence of shipbuilding with roots dating back at least to the Bronze Age (around 3,300 to 1,200 BCE).
“The boat was used by a small army of invaders who attacked the island of Als in southern Denmark more than 2,000 years ago,” the team wrote. “The invaders were defeated and the local defenders sank the boat in a bog as an offering to thank them for their victory.”
The boat was first discovered in a bog on the Danish island of Als in the early 1920s and has remained a mystery ever since. Archaeologists have not yet determined where these warriors came from and when.
“The boat was excavated before modern dating methods were available and most of the boat’s materials were immediately preserved using chemicals that make radiocarbon dating impossible,” the team said. “By going through the archives, however, we were able to find original ropes that had not been preserved. We obtained a radiocarbon date of the rope that returned a date range in between.”
Ancient sailor’s fingerprint found on Scandinavia’s oldest plank ship
CREDIT: Lund University.
Pine Terrain and Prints
In this new study, a team from Lund University in Sweden searched for more clues about the boat’s origins. Over the past 100 years, several theories about the origin of the boats have been proposed, according to which the invaders came from northern Germany or another part of present-day Denmark.
“The weapons they used, which were found in the boat, were quite common for the time and were used throughout northern Europe, giving us little clue as to their origin,” the authors say.
The team carbon-19 dated and analyzed some previously unstudied caulking and cording materials found with the boat. The caulking used to seal the boat was probably made from a mixture of pine pitch and animal fat.
According to the team, this pine trail is the first major new showing in more than a century. When the ship was built, Denmark itself had few pine forests. While it is possible that pine pitch came to Denmark via trade, other coastal areas in eastern Denmark along the Baltic Sea had pine forests.
The team believes it is possible that the ship was built here and its warriors came to Als from the east. If this is true, the ship sailed offshore to reach southern Denmark. Traveling such a long distance potentially indicates that the attack was well organized and premeditated.
Based on carbon dating of the ropes and caulking, the boat was likely built between 381 and 161 BCE, confirming that it was built in the pre-Roman Iron Age. This timeline also matches previous estimates of timber from the Hjortspring site.
However, there was another clue worth noting: the partial human fingerprint in the caulking material used to waterproof the boat. Although they could not determine exactly who left it as modern fingerprint analysis allows, it was likely left by one of the ship’s crew, “providing a direct link to the sailors of the old ship.”
With pine pitch clues and now some fingerprints, we are getting closer to solving this Iron Age boat mystery.
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