Discovering History on the Ocean’s Floor

Archeologist Brendan Foley scours shipwrecks for clues to how we used to live

Thirty feet under the surface of the cold, murky Baltic Sea, Brendan Foley spotted something unusual in the wreckage of an ancient ship. Foley, AG95, a marine archaeologist and researcher at Lund University in Sweden, was clearing mud away from a wooden tankard wedged beneath a tangle of firewood when the tankard began to move on its own, pulling free of the sediment and rising quickly toward the surface.

“I hadn’t seen an artifact try to escape before,” Foley said. “I had to hold it down.”

He flipped the tankard over, releasing bubbles of gas that had been trapped inside—remnants from the decomposition of the beer or mead it was holding more than 500 years ago, when the ship went down. Foley was excavating a portion of the Gribshunden, a remarkably well-preserved royal Danish flagship that sank off the coast of Sweden in 1495, likely due to a gunpowder explosion.

“The tankard must have been dropped by someone on board when the ship exploded,” Foley said. “To be able to hold something like that—it’s a direct connection to the people in that event.”

Brendan Foley takes notes on board a boat

Brendan Foley has devoted his career to unearthing what's been lost in the ocean. Here he’s shown in 2021 at work on a preliminary survey of the wreck of a U.S. bomber that was shot down off the coast of Sweden during World War II. Photo: Christoffer Bergstrand

Foley has spent his career unearthing what we’ve lost under the ocean. He has surveyed the depths of the Mediterranean Sea aboard a nuclear submarine; led dives to excavate shipwrecks from ancient Greece and Rome; and hunted for evidence of sunken ships in the Black Sea with remotely operated vehicles. He has also worked with U.S. Department of Defense to recover the remains of service members from planes that crashed in the ocean during World War II.

On his dives to shipwrecks, he has discovered coins, jewelry, a bronze arm from a life-sized statue, and many other intriguing artifacts. But it’s not the objects themselves that he finds captivating; it’s what they can tell us about how people lived and moved through the world.

“Shipwrecks are like telephone calls—they’re packets of information,” Foley said. “And with the right technology and the right experts and insights, we can eavesdrop on these ancient telephone calls and reconstruct that conversation.”

This is what makes the Gribshunden, the ship that Foley is currently excavating in the Baltic, so valuable. The Gribshunden was the personal flagship of King Hans of Denmark and Norway, and it sank while he was traveling to a political summit in Kalmar, Sweden, where he expected to unify the entire Nordic region under his crown. The floating castle sank at anchor, while King Hans was ashore, taking with it all the symbols of power that the king and his nobles had brought with them. Local divers originally found the wreck in the early 1970s, but it didn’t come to the attention of archaeologists until 2001, and excavation had been fairly limited until Foley joined the team in 2018.

“We’ve found things on this site that have no precedent archeologically,” Foley said. “Everything about it is fascinating.”

The Gribshunden represents the first generation of artillery-carrying warships, akin to the large, heavily armed ships that Vasco da Gama used to reach India and Columbus used to reach the Americas. The design of these ships made long-distance voyages possible, allowing Europeans to conquer, colonize, and exploit large portions of the globe.

But the Gribshunden is better preserved than other shipwrecks from that era. The low salinity of the Baltic Sea has kept wood-eating shipworms from devouring the hull and any other wood on board. Foley and his colleagues have excavated only between 1% and 2% of the site, but what they have brought to the surface will keep scholars busy for years, he said.

Their finds include several intact wooden crossbows, early handguns, and other weaponry, a collection that marks the beginning of the transition toward gunpowder weapons. Crossbows may have been more reliable and better suited to hunting, but the handguns could have been a mark of prestige or a sign of military strength.

The archaeologists also retrieved a purse of silver coins and were able to determine when and where they were minted, pointing to a shift away from barter economies and toward the use of money around this time. They even unearthed an assortment of the king’s exotic spices, including cloves, peppercorns, pieces of ginger, and fist-sized lumps of saffron. These expensive luxuries would have been imported from as far away as modern-day Indonesia and were intended to season the elaborate feasts at Hans’ political summit.

Even the tankard that tried to escape Foley’s grasp is unique. Analysis showed that it was made from a single piece of alder wood—likely turned on a lathe—and had originally been painted red, with the shape of a crown carved near the base. The interior still smells faintly of pine, suggesting that it may once have held a pine-flavored beer, and it doesn’t resemble any other known drinking vessels from that time, Foley said. It could have been made specifically for the Gribshunden.

“Hans used this [ship] as a military fortress, but also as an administrative center, as a cultural center, as a basis for his economic policies,” Foley said. “We’re finding evidence of all of this in the artifacts on board the ship.”

Brendan Foley and others stand on a boat while a diver enters the water

Brendan Foley supervises as another archaeologist enters the water at the Gribshunden wreck site in 2022. “We’ve found things on this site that have no precedent archeologically,” he said. “Everything about it is fascinating.” Photo: Brett Seymour

Foley has always been fascinated by the ocean and what lies beneath it. Growing up along the coast of Massachusetts, north of Boston, he was an avid diver and intended to study at the U.S. Naval Academy in Annapolis until a serious injury derailed those plans. Instead, he attended the University of New Hampshire and earned his last few college credits at a maritime archaeology field school, studying a Colonial-era wreck in the Piscataqua River.

The hands-on experience helped Foley realize that he wanted to lead underwater archaeological expeditions of his own. He went on to earn a master’s degree in history from Tufts, a second master’s in maritime archaeology from the University of Southampton in England, and finally a Ph.D. from MIT while working with the Deep Submergence Laboratory at the Woods Hole Oceanographic Institution, where he would remain on staff as a marine archaeologist for 10 years.

“I can’t imagine doing anything else,” he said. “Since I was a teenager, I’ve never been able to look at a body of water without wondering what’s on the bottom.”

For the moment, the Gribshunden is keeping Foley busy. But there are other questions that he wants to investigate and other depths that he wants to explore. The Gribshunden’s impressive preservation reminds him of sunken ships he saw through the camera of a remotely operated vehicle 20 years ago in the Black Sea. In the oxygen-depleted depths, the ships were perfectly preserved, with their masts and rigging still standing. The Caspian Sea, which is virtually unexplored, has very similar characteristics.

Foley is “salivating at the thought” of conducting broad surveys of the unexplored parts of the Baltic, Black, and Caspian seas, using autonomous underwater vehicles. Ships facilitated local and global exchange, shaping the evolution of early societies and modern civilization. Any place where they are well preserved could be a treasure trove of new information about how we ended up here.

“It’s not just about making discoveries, it’s about fundamentally new knowledge about our existence on this planet,” Foley said. “I’ve seen a little bit of what’s out there, and I understand the potential of what could be discovered. But sometimes even my imagination can’t keep pace with what’s really there.”

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