Excerpts from Books and Wikipedia
"The Hanseatic League came to dominate the Baltic trade, and as their business expanded, the merchants formed guilds, or 'Hansa,' to protect their mutual interests and to protect against piracy. . . . over time, the league came to form a network of informal alliances involving more than seventy cities and towns. Lubeck remained the most important of the Hansa cities, and was often referred to as 'Queen of the Hansa.'. . . The league's influence was at its greatest in the mid-fourteenth century, but in the fifteenth century, regional differences began to weaken the bonds that held the members together. In the sixteenth century, the rise of the Dutch as trading rivals further weakened the league, and when trade with the New World expanded, the league went into a sharp decline form which it never recovered. The last diet was held in 1669." [1001 Days] The League was founded in 1158. "This marks a new period of trade and economic development for northern and central Europe." [Wikipedia: Timeline of Middle Ages]