Maritime archaeologists from the Viking Ship Museum in Denmark have discovered the world’s largest cog – a sturdy, versatile cargo and warship common in northern Europe from the 10th to 17th centuries.
The medieval cargo ship, whose size and previously unknown construction details offer new insight into the maritime technology and trade networks of the Middle Ages, also sheds light on the scale and organisation of medieval trade across northern Europe.
The find was made in the Sound or Øresund, the strait between Denmark and Sweden, during seabed investigations for Copenhagen’s new district, Lynetteholm.
According to the Viking Ship Museum report announcing the discovery, from the very first dive, the maritime archaeologists sensed they had uncovered something extraordinary.
As they removed centuries of sand and silt, the outline of a remarkable find emerged.
Not just any wreck but the largest cog ever discovered, a ship that represents one of the most advanced vessel types of its time and the backbone of medieval trade.
“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 maritime archaeologist and excavation leader, Otto Uldum.
The ship, named Svælget 2 (Svaelget) after the channel where it was found, is approximately 28 metres long, nine metres wide and six metres high, with an estimated cargo capacity of 300 tonnes.
Built around 1410, the cog represents the largest example of its type ever discovered anywhere in the world.
According to the archaeologists, a ship of this size reflects a society in transition, because such a vessel required a well-established trade structure.
“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,” said Uldum.
The cog was an efficient ship type that could be sailed by a remarkably small crew, even when heavily loaded. Large cogs were built to make the hazardous voyage around Skagen from what is now the Netherlands through the Sound and reaching the trading towns of the Baltic.
Svælget 2 points directly to the extensive trade networks that bound northern Europe together in the 15th century.
“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,” said Uldum.
The cog was the super ship of the Middle Ages. Developed in the North Sea region, it made it possible to transport large quantities of goods efficiently and at low cost. This ship type was central to economic development in the 14th and 15th centuries, and with its enormous cargo capacity, it transformed trade patterns. Where long-distance trade had previously been limited to luxury goods, everyday commodities could now be shipped across great distances.
“The cog revolutionised trade in northern Europe. It made it possible to transport goods on a scale never seen before,” said Uldum.
Source: Vikingeskibs Museet (Viking Ship Museum)
