The Hanseatic League was a confederation of merchant guilds and market towns around the North and Baltic Seas that coordinated long-distance trade from the twelfth century, holding its first general diet around 1356. At its height it linked some two hundred towns from Novgorod to London, securing trading privileges, common commercial law and protection for its members, with a network of warehouses and offices called Kontore. Member cities such as Lübeck, Hamburg and Danzig grew wealthy on the trade in grain, timber, fish, salt and cloth, building distinctive brick-gabled warehouses and merchant houses. The League had no single capital or standing army, governing instead through negotiated agreement between its towns.
It was an early trans-national urban network, showing how cities could pool sovereignty for commercial ends and leaving a shared mercantile building culture across the Baltic.