Historical story

The spacious ship type Kogge was central to seafaring and trade between the medieval Hanseatic cities

Following the medieval Italian trade centers in luxury products, Northern European cities also concluded a trade union:the Hanseatic League. From the twelfth century, trade provided wealth and much-needed consumer goods for the growing cities. The ship that sailed between the Hanseatic cities was the cog. With this spacious ship type, traders mainly transported bulk goods throughout Europe.

The cog is actually quite a mystery. The heyday of this ship type is between 1200 and 1400, but no one knows when the first cog was made. Shipbuilders shared their knowledge verbally with the apprentices, so there are no blueprints for these ships. Cogs only appear in official documents, for example about toll collection or sales.

The oldest mention of a cog seems to date from the mid-tenth century. The present Netherlands was part of the Holy Roman Empire and the later emperor Otto I granted the bishop of Utrecht the right to levy tolls on (mainly Frisian) ships. The old Frisians called this toll kogskult.

There is even a theory that the name kogge occurred before and is named after the inhabitants of West Frisia (approximately the current Dutch coastal strip), who are known as Coginki be on record. In 867, these seafaring people revolted against the Danish Viking Rorik, who was duke of that area at the time. In any case, this round-bellied ship would find its way to the Mediterranean from 1180 through trade contacts and inspire the Italians to build similar ship types.

Oak wood and moss

Shipbuilders had no set guidelines for building a cog. The length varies, for example, from fifteen to thirty meters. However, the ships do have some common features:a flat bottom, a hull of clinker planks (planks that overlap like roof tiles), a steep bow and stern (where the ship's hull meets; the stern is now also called transom and the stern bow) and a mast with a single rectangular sail.

Cogs were made of oak wood. Not only because there were many oaks in the area, but also because it is very suitable wood to work with. Dry oak is strong and hard, but with the help of water and fire it becomes more flexible and you can bend oak planks. In addition, it is relatively resistant to fungi and insects. To close the gaps between the planks, shipbuilders put moss between them. Moss was also everywhere and therefore cheap. A good thing about moss was that it swells when it comes into contact with water. That way no water got in.

Hungry townspeople

The flat bottom of a cog was very important because it provided a lot of cargo space. The average cog could hold a hundred times the load of a single cartload. With the rapid growth of the cities from the twelfth century, and with it the inhabitants to be fed, a lot of cargo space was very important.

In addition, a cog could sail day and night, which also made transport a lot faster than traveling over land. Good naval instruments did not yet exist, so the cogs mainly sailed along the coastline. They could see where they were from landmarks on land such as high church towers.

To promote growing international trade, buy cheaper and travel more safely together, traders in different cities made connections with each other. Together they were also stronger against noblemen who wanted to impose all kinds of taxes. These alliances became 'Hanseatic' called, meaning "group" in Old High German.

In 1356, several German trading towns entered into an alliance at the initiative of the city of Lübeck. The German cities were not alone, but of the various Hanseatic League in Europe, the German alliance grew to become the most powerful of all. Other cities in North-West Europe also joined this German Hanse; from Russian Novgorod in the east to London in the west. At the height of the Hanseatic League, almost two hundred cities would have special treaties with each other and seventy of them were members of the city alliance.

Transit ports in the Netherlands

Several Dutch cities also joined the German Hanse, such as Kampen, Deventer, Zutphen and Zwolle. Their ships sailed via the Zuiderzee – now the IJsselmeer – into the North Sea towards Scandinavia and the Baltic countries near the Baltic Sea. The traded products were very diverse. From the Baltic Sea came grain, fur, the much-needed wood for building houses, and wax for the many candles that were lit in the churches. Scandinavia supplied salted herring, textiles from England and Flanders, and the Germans supplied minerals and beer for daily use instead of the dirty drinking water.

Trade flourished as never before and the cities grew richer and larger. Hanseatic merchants lived together in special neighborhoods for optimal contact and on special Hanseatic days the members met and made decisions. The Hanseatic League was active for centuries, but in the seventeenth century the alliance died a slow death. This was not due to the trade:it only continued to grow and increasingly larger ships are now sailing all over the world.

Cities became a lot more autonomous during this period than in the centuries before and the once successful cooperation slowly crumbled. The Thirty Years' War in the German Empire (1618-1648) also contributed to the downfall of the Hanseatic League. The cities in Zeeland and Holland – especially Amsterdam – had taken over the trading baton and in 1669 the Hanseatic League was officially over. The curtain had already fallen for the cog. This 'Queen of the Hanseatic League' had her heyday between 1200 and 1400 and was then gradually replaced by larger variants with even more loading capacity.

The IJsselkogge

In 2012, the wreck of a complete cog was found in the IJssel, in front of the port of the Hanseatic city of Kampen. The (underwater) survey commissioned by Rijkswaterstaat has almost been completed and the wreck will be lifted at the beginning of February 2016. Read more about the technical aspects of this research and the interview with professor of maritime archeology André van Holk about medieval water management and the function of the IJsselkogge.

Read the other articles in this triptych

'Middle Ages really weren't stupid'

Marjolein Overmeer

Shipwreck paradise in the IJssel floor

Roel van der Heijden