Eventually, some of these cities began to form alliances with other cities, forming 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 gave access to 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. 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 Hansa 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 (present Estonia and Latvia) had its own Hanseatic parlament (diet) and all of its major towns were members of Hanseatic League.

Eventually, the capital of Hansa were moved to Danzig, which was the main port for Polish merchandise brought up the Vistula river. Other important cities, members of Hansa were Thorn ([[Torun), Elbing, Koenigsberg and Polish Krakow.

The League was fluid in nature, but its members shared some traits. First, most of the Hanseatic League (or Hansa) cities either were founded as independent cities or gained independence through the collective bargaining power of the League. Independence in this case was limited; it meant that the cities owed allegiance directly to the 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 Hansa 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 had all but imploded, 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 Hansa cities. For Lübeck in particular, this anachronistic tie to a glorious past remained especially important in the second half of the 20th century.

List of members

• Gdansk (capital)
• Wroclaw
• Krakow
• Szczecin
• Torun
• Elblag
• Hamburg
• Bremen
• Deventer
• Kampen
• Zutphen
• Lübeck
• Rostock
• Wismar
• Stralsund
• Greifswald
• Anklam
• Reval
• Pernau
• Dorpat
• Fellin
• Riga
• Windau
• Goldingen
• Wolmar

• http://www.hanse.org\n