As a consequence of the monopoly that Lüneburg had for many years as a supplier of salt within the North German region, a monopoly not challenged until much later by French imports, it very quickly became a member of the Hanseatic League. The League was formed in 1158 in Lübeck, initially as a union of individual merchants, but in 1356 it met as a federation of trading towns at the first general meeting of the Hansetag. Lüneburg's salt was needed in order to pickle the herring caught in the Baltic Sea and the waters around Norway so that it could be preserved for food inland during periods of fasting when fish (not meat) was permitted.
The Scania Market at Scania in Sweden was a major fish market for herring and became one of the most important trade events in Northern Europe in the Middle Ages. Lüneburg's salt was in great demand and the town quickly became one of the wealthiest and most important towns in the Hanseatic League, together with Bergen and Visby (the fish suppliers) and Lübeck (the central trading post between the Baltic and the interior).