Final answer:
The establishment of the Hanseatic League was significant as it revitalized trade routes in Europe and led to the growth of city-states and the development of modern commercial infrastructure.
Step-by-step explanation:
The establishment of the Hanseatic League in 1241 c.e. was considered significant because it played a crucial role in revitalizing trade routes in Europe. The league, which consisted of merchants and trading cities in the Baltic and northern regions, created a network economy that connected Europe for the first time since the 4th century. This led to the growth of city-states, the development of modern commercial infrastructure, and the expansion of international trade.