In a groundbreaking underwater expedition off the Swedish coast, archaeologists have unveiled the astonishing secrets of a 15th-century royal warship that once served as a formidable “floating castle” for a fearless king. This remarkable discovery sheds light on a vessel equipped with cannons, handguns, crossbows, and an imposing stern superstructure.
The newly unearthed remnants of the Gribshunden, the flagship of King Hans (or John) of Denmark until its sinking in 1495, paint a vivid picture of a vessel that sailed as a fearsome warship, armed with scores of cannons and packed with soldiers.
While the Gribshunden may have boasted up to 90 early cannons, albeit smaller than the ship-smashing cannons of the late 16th century, its might was complemented by armored soldiers armed with handguns and crossbows stationed on the ship’s upper deck, forecastle, and sterncastle – the towering superstructures at each end of the ship.
Measuring an impressive 115 feet in length, this wooden ship represented cutting-edge technology for its era, employing the “carvel” shipbuilding technique imported to the Baltic from the Mediterranean. This method involved joining hull planks edge-to-edge on a wooden frame rather than overlapping them, allowing the Gribshunden to be constructed larger and stronger than ships with lapstrakes, making it more capable of navigating treacherous seas.
Breandán Foley, a maritime archaeologist at Lund University in Sweden leading the latest excavations, explains, “This is kind of a new technology. It was designed to carry artillery, and King Hans uses the ship in a way that no other king does.”
From the mid-1480s, King Hans frequently embarked on the Gribshunden throughout his realm, often accompanied by a sizable royal fleet, in a bid to assert his dominance over his rivals. Haas ruled Denmark from 1481 and added the crown of Norway in 1483, but Sweden didn’t submit to his rule until 1497.
His realm encompassed Denmark and Norway, and he aimed to persuade Sweden to rejoin the Nordic Union. “So Hans is sailing around on this ship all the time,” says Foley. (The Nordic Union of Denmark, Norway, and Sweden was also known as the Kalmar Union, named after the town in Sweden where it was established in 1397.)
In 1495, while negotiating at Kalmar, the Gribshunden mysteriously sank, supposedly due to a fire, at an anchorage just off the town of Ronneby. King Hans and his retinue were onshore at the time, but a witness to the catastrophe reported that many of the approximately 150 men onboard perished.
Numerous cannons from the ship were likely salvaged shortly after its sinking, as the latest excavations uncovered only 14 cannon carriages near the stern, though many more were probably situated near the bow.
A unique aspect of the eastern Baltic Sea is its unsuitability for shipworm infestations, owing to its cold and brackish waters. This has ensured the preservation of the wooden gun carriages, even though the iron cannons have corroded away.
However, there is no evidence of a fire, suggesting that the ship likely sank rapidly after being breached below the waterline, possibly due to an explosion of its gunpowder stores. “It’s one of the first ships carrying gunpowder, so they probably hadn’t worked out standard operating procedures for safety,” Foley speculates.
Local divers rediscovered the Gribshunden wreck near Ronneby in the 1970s, lying beneath approximately 33 feet (10 meters) of water. It was positively identified in 2013, and in 2015, archaeologists retrieved several artifacts, including a figurehead depicting a person clutched in the jaws of a dog or dragon.
Foley led dives to the wreck in August and September, during which the team recovered additional artifacts and captured three-dimensional data for digital reconstruction.
The Gribshunden is considered a proxy for ships from the Age of Exploration, such as those of Christopher Columbus and Vasco da Gama, which were constructed around the same time but are now lost. “Nothing else like this has ever been found,” Foley asserts.
The combination of cannons and crossbows, along with the remnants of mail armor shirts found, exemplifies the transition from earlier weaponry to gunpowder. The ship’s larger cannons were mounted on swivels within their wooden carriages and fired projectiles roughly the size of golf balls. Meanwhile, the handguns were relatively simple, measuring about 16 inches (40 centimeters) long, with projectiles similar to musket balls that were fired by touching a match to a hole in the back. “They were basically like a small cannon,” Foley explains.
Fritz Jürgens, a maritime archaeologist at Kiel University in Germany not involved in the study of the Gribshunden, is leading research into a rare 400-year-old ship discovered in the outer stretches of the Trave River in the western Baltic. He notes that the Gribshunden is the oldest carvel-built ship ever found in the Baltic and one of the oldest purpose-built warships ever discovered.
“In the Middle Ages and in the later Hanseatic period, they took regular cargo ships and put archers on them,” Jürgens states. “But the Gribshunden had artillery on the forecastle and sterncastle – it was specifically built for war.”
