Hanseatic Leaguetrading cities that for a time in the later Middle Ages and the Early Modern period maintained a trade monopoly over most of Northern Europe and the Baltic, can be seen as early as the 12th century. At about this time, merchants in a given city began to form societies, or Hanse, with the intention of trading with foreign cities. These societies worked to acquire special trade privileges for their members. For example, the merchants of Cologne were able to convince Henry II of England to grant them special trading privileges and market rights in 1157.
Eventually, some of these cities began to form alliances with other cities, in a loose network of mutual assistance that would become the Hanseatic League. The chief city of the Hanseatic League was Lübeck, founded by Henry the Lion of Saxony in 1159. Its location on the Baltic provided access for trade with Scandinavia and Russia, putting it in direct competition with the Scandinavians who had previously controlled most of the Baltic trade routes. Competition was ended through a treaty with the traders of Gotland. Through this treaty, the Lübeck Merchants also gained access to the Russian port of Novgorod, where they built a trading post. Lübeck, which had access to the Baltic and North Sea fishing grounds, later formed an alliance with Hamburg, another trading city that controlled access to salt routes from Lueneburg. The allied cities were able to gain control over most of the salt fish trade. Other such alliances formed throughout the Holy Roman Empire. Over time, the network of alliances grew to include upwards of 100 cities.
The German colonists built numerous Hanse towns in the Baltics like Reval (Tallinn), Riga, Dorpat (Tartu), some of which are still filled with buildings and style from their Hanseatic days. Livonia (presently Estonia and Latvia) had its own Hanseatic parliament (diet) and all of its major towns were members of Hanseatic League.
Eventually, the Hanse capital of was moved to Danzig, which was the main port for German merchandise brought up the Vistula river. Other important cities which were members of the Hanse were Thorn, Elbing, Koenigsberg and Kraków.
The League was fluid in nature, but its members shared some traits. First, most of the Hanseatic League (or Hanse) cities either were founded as independent cities or gained independence through the collective bargaining power of the League. Independence was however limited; it meant that the cities owed allegiance directly to the respective Emperor, without any intermediate tie to the local nobility. Another similarity was that the cities were all strategically located along trade routes. In fact, at the height of its power, the merchants of the Hanseatic League were sometimes able to use their economic power (and sometimes their military might -- trade routes needed protecting, and the League's ships were well-armed) to influence Imperial policy. The League also wielded power abroad: between 1368 and 1370, the League's ships fought against the Danes, and forced the Danish king to grant the League 15 percent of the profits from Danish trade (Treaty of Stralsund).
Exclusive trade routes often came at a high price. In most foreign cities, the Hanse traders were confined to certain trading areas and to their own trading posts. They were seldom, if ever, allowed to interact with the local inhabitants, except in the matter of actual negotiation. Moreover, the power of the League was envied by many, merchant and noble alike. The very existence of the League and its privileges and monopolies created economic and social tensions that often crept over into rivalry between League members. By the late 16th century, the League imploded and was unable to deal with its own internal struggles, the social and political changes that accompanied the Reformation, the rise of Dutch and English merchants and the incursion of the Ottoman Turks upon its trade routes and the Empire itself.
Despite its demise, several cities still maintain the link to the Hanseatic League. Even in the 21st century, the cities of Deventer, Kampen, Zutphen, Lübeck, Hamburg, Bremen, Rostock, Wismar, Stralsund, Greifswald and Anklam call themselves Hanse cities. For Lübeck in particular, this anachronistic tie to a glorious past remained especially important in the second half of the 20th century. Lübeck was also, as the other main cities, a "Free and Hanse City" as is still, for example Bremen. This privilege was removed by the Nazis after the Senat of the Hanse City did not permit Adolf Hitler to speak in Lübeck during his election campaign. He held the speech in Bad Schwartau, a small village at the outskirts of Lübeck. He later referred to Lübeck always as "the small city close to Bad Schwartau"