Weapons chest found on wreck of 15th-century 'floating castle' sheds light on 'military revolution at sea'

Underwater archaeologists in Sweden have determined that a chest in the wreck of a 15th-century warship held tools to make lead shots for early handguns. The finding hints at key changes in naval battles at the time.

The chest is in the wreck of the Gribshunden ("Griffin hound"), a Danish royal "floating castle" that sank in 1495 at an anchorage in southern Sweden after a fire attributed to the mishandling of gunpowder.

The discovery could shed new light on the fate of the vessel, according to Rolf Warming, a maritime archaeologist and doctoral student at Stockholm University. Warming co-authored a new report on the weapons chest and other new finds from the Gribshunden wreck with Johan Rönnby, a maritime archaeologist and professor at Södertörn University in Sweden. The wreck was discovered by recreational divers in the 1970s, and Rönnby has studied it since 2013.

The discovery also hints at an early development in naval warfare from ramming and engaging in hand-to-hand combat — the tactics used since ancient times — to attacking enemy ships at a distance with gunfire, Warming said. But he stressed that it took more than a century for the development to become widespread.

"This is very much at the beginning of what we call the 'military revolution at sea,'" Warming told Live Science. "The tactics and technology for that were only fulfilled in the second half of the 17th century."

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Weapons chest

Warming and Rönnby used photogrammetry, a technique that involves digitally stitching together photos, to create a precise, virtual 3D model of the weapons chest. The chest is still underwater at the wreck site in coastal islands near the Swedish town of Ronneby, but Warming hopes it will be recovered soon. Conserving its contents will be a lengthy process, he said.