Archaeologists Discover Massive 600-Year-Old Cargo Ship, Largest of Its Kind Ever Found

Archaeologists have uncovered a massive cargo ship dating back 600 years beneath the Øresund Strait, the stretch of water separating Denmark and Sweden. Believed to be the largest medieval cog ever discovered, the ship was found 40 feet underwater and is remarkably intact.

Researchers from Denmark’s Viking Ship Museum located the wreck, named Svaelget 2, during a routine seabed survey. Measuring approximately 92 feet long, 30 feet wide and 20 feet high, the vessel is thought to have carried up to 300 tons of goods, indicating it played a major role in northern Europe’s medieval trade routes.

Otto Uldum, the lead archaeologist on the project, said the find is a rare opportunity to examine how such large trading ships were constructed and operated. He added that the size of the ship reflects a thriving economic system at the time, one capable of funding and building complex vessels meant for transporting heavy cargo across long distances.

Ancient trade powerhouse revealed

First used around the 10th century, cogs were designed for shipping large volumes of goods more safely and efficiently than earlier vessels. Their deep cargo holds and tall sides gave them both capacity and protection during sea travel.

The museum explained that ships like Svaelget 2 typically sailed from the Netherlands, around Denmark, and into the Baltic Sea. Despite their scale, they could be managed by small crews.

Although no cargo was found with the wreck, the team recovered everyday items used by the crew, including leather shoes, combs and rosary beads.

Uldum explained that while the ship no longer held its original freight, these personal objects offer insight into the daily life of sailors on board.

Rare features found on massive cargo ship

One of the most surprising discoveries was the ship’s stern, where archaeologists found the preserved remains of a covered deck structure known as a castle. Historical records often depict these shelters, but this marks the first time physical evidence has been recovered. Uldum noted that such features are usually lost, as most wrecks only preserve the lower parts of vessels.

The ship also contains a brick-built galley where food was prepared. Constructed from about 200 bricks and 15 tiles, the fireproof cooking area still held bronze pots, wooden plates and remnants of meat and fish.

Dendrochronological analysis revealed that Svaelget 2 was built around 1410. Its planks were made from oak sourced in present-day Poland, while the frame came from the Netherlands.

Uldum said the discovery doesn’t rewrite the history of medieval trade, but it confirms that cogs could be built at this scale. He called Svaelget 2 clear proof of how such massive cargo ships helped shape European commerce during the Middle Ages.