PREVIEW

WORDS BYLINE: Hayley Chamberlain

A 600-year-old ‘medieval super ship’ bigger than anything seen before has been pulled from the depths off Denmark – and it is rewriting the history of European trade.

For centuries, the waters between Denmark and Sweden concealed an extraordinary secret. Now maritime archaeologists from the Viking Ship Museum have revealed the discovery of the world’s largest cog – a colossal medieval cargo vessel whose sheer scale and remarkable preservation are offering unprecedented insight into life and commerce in the Middle Ages.

The wreck was uncovered in the Sound (Øresund) during seabed investigations linked to the construction of Copenhagen’s vast new Lynetteholm district. From the very first dive, experts realised they were dealing with something special. As layers of sand and silt were carefully removed, the outline of a truly gigantic ship began to emerge.

Not just any wreck – but the largest cog ever discovered anywhere in the world.

‘The find is a milestone for maritime archaeology. It is the largest cog we know of, and it gives us a unique opportunity to understand both the construction and life on board the biggest trading ships of the Middle Ages,’ said excavation leader Otto Uldum.

Named Svælget 2 after the channel where it was found, the ship dates back to around 1410 and measures an astonishing 28 metres (92ft) long, nine metres (30ft) wide and six metres (20ft) high. Experts estimate it could have carried up to 300 tonnes of cargo – an eye-watering capacity for its time.

According to archaeologists, a ship of this magnitude reflects a society undergoing dramatic change.

‘A ship with such a large cargo capacity is part of a structured system where merchants knew there was a market for the goods they carried. Svælget 2 is a tangible example of how trade developed during the Middle Ages,’ Mr Uldum said.

Cogs were the workhorses of medieval Europe – efficient, robust and capable of being sailed by relatively small crews, even when heavily laden. Vessels like Svælget 2 would have made the treacherous journey around Skagen, sailing from what is now the Netherlands through the Sound and on to the bustling trading towns of the Baltic.

‘It is clear evidence that everyday goods were traded. Shipbuilders went as big as possible to transport bulky cargo – salt, timber, bricks or basic food items,’ Mr Uldum explained.

Developed in the North Sea region, the cog revolutionised trade in the 14th and 15th centuries, making it possible to transport everyday commodities over long distances for the first time.

‘The cog revolutionised trade in Northern Europe. It made it possible to transport goods on a scale never seen before,’ Mr Uldum said.

Scientific analysis of the timber has revealed just how international this operation was. Tree-ring dating shows the ship was built using oak from two different regions: planks from Pomerania in modern-day Poland, and frames from the Netherlands.

‘It tells us that timber exports went from Pomerania to the Netherlands, and that the ship was built in the Netherlands where the expertise to construct these very large cogs was found,’ Mr Uldum said.

Perhaps most remarkable of all is the ship’s condition. Lying at a depth of 13 metres, Svælget 2 was protected by thick layers of sand that shielded it from destructive coastal forces. The starboard side survives almost intact, from keel to gunwale – something never before seen in a cog.

Among the most groundbreaking discoveries are extensive remains of the ship’s rigging, as well as the first-ever archaeological proof of the famous castles often depicted in medieval drawings.

‘We have plenty of drawings of castles, but they have never been found because usually only the bottom of the ship survives. This time we have the archaeological proof,’ Mr Uldum said.

The timber-built stern castle – a covered deck where the crew could shelter from the elements – represents a major leap forward from earlier Viking-age vessels.

‘We now have 20 times as much material to work with. It is not comfort in a modern sense, but it is a big step forward compared to Viking Age ships, which had only open decks in all kinds of weather,’ he added.

Another surprise lay in the heart of the ship: a brick-built galley, the earliest example ever found in Danish waters. Around 200 bricks and 15 tiles formed a solid cooking area where sailors prepared meals over an open fire.

‘We have never before seen a brick galley in a medieval ship find from Danish waters. It speaks of remarkable comfort and organisation on board. Now sailors could have hot meals similar to those on land, instead of the dried and cold food that previously dominated life at sea,’ Mr Uldum said.

Nearby, archaeologists found bronze cooking pots, ceramic bowls and remains of fish and meat – alongside hundreds of finely cut sticks believed to have been used for stockfish.

The excavation has also revealed deeply personal traces of the crew: painted wooden bowls, shoes, combs and rosary beads.

‘The sailor brought his comb to keep his hair neat and his rosary to say his prayers. We have the remains of the pots his food was cooked in and the bowls he ate from. These personal objects show us that the crew brought everyday items with them. They transferred their life on land to life at sea,’ Mr Uldum said.

Despite its vast size, no trace of the ship’s cargo has been found.

‘We have not found any trace of the cargo. There is nothing among the many finds that cannot be explained as personal items or ship’s gear,’ Mr Uldum said.

Experts believe barrels of salt, bundles of cloth or timber would have floated away as the uncovered hold filled with water. The lack of ballast suggests the vessel was loaded to the brim with heavy trade goods. Crucially, there is no sign the ship was ever used for war.

‘There is no evidence pointing to war or conflict in this ship. None at all,’ Mr Uldum stressed.

Now undergoing conservation at the National Museum in Brede, Svælget 2 is being hailed as a concrete witness to a turning point in European history.

‘It required a society that could finance, build and equip these enormous ships that served the Middle Ages’ need for export and import over great distances,’ Mr Uldum said.

And while it may not rewrite history entirely, the ship leaves no doubt about what medieval technology could achieve.

‘We now know, undeniably, that cogs could be this large – that the ship type could be pushed to this extreme. Svælget 2 gives us a tangible piece of the puzzle and makes it possible to understand how technology and society evolved side by side in an era when shipping was the driving force behind international trade.’