The Hanseatic League was a powerful trading alliance of cities in northern Europe during the Middle Ages. The four cities that make up the term HANSEATIC LEAGUE CITY are HAMM, GDANSK, LUBECK, and BREMEN. HAMM is a city in Germany, GDANSK is a port city in Poland, LUBECK is a city in Germany, and BREMEN is a city in Germany. All four cities were part of the Hanseatic League and played an important role in its success.