In the conflict between the Hanse and Denmark on the trade in the Baltic King Valdemar IV of Denmark had held the Hanseatic city of Visby to ransom in 1361. However, the members of the Hanseatic league were undecided to unite against him. However, when Valdemar IV then captured Prussian merchant ships in the Øresund on their way to England, Grand Master Winrich of Kniprode travelled to Lübeck to propose a war alliance against Denmark, received with reluctance only by the important cities forming the Wendish-Saxon third of the Hanse.