During great parts of the Middle Ages, most Baltic trade was controlled by the Hanseatic League, a huge and powerful trading company. It had great economical and political power for many hundreds of years.
The Hanseatic league started in the 12th century as a league of merchants from Northern Germany, trading the Baltic and the North Sea. This was known as the merchant Hansa. In the course 14th century, the Hansa was transformed into a league of towns in with Lübeck played the leading role.