The Hanseatic League was an alliance of trading cities that established and maintained a trade monopoly over the Baltic Sea and most of Northern Europe for a time in the later Middle Ages and the Early Modern period, between the 13th and 17th centuries.
Trade was carried on chiefly by sea in order to escape tolls and political barriers, and at the end of the 15th century the Hanseatic League controlled some 60,000 tons of shipping.