The Hanseatic League was a commercial and defensive alliance of merchant guilds and towns in northern Europe from the late 12th century to the 17th century. It aimed to protect trade routes and promote economic interests among its members, which included cities like Hamburg, Lübeck, and Bremen. The League established a network of trading posts and settlements, facilitating trade in goods such as timber, fish, and textiles. It played a significant role in the economic development of the Baltic Sea and North Sea regions, influencing trade policies and practices during its peak.