[1][2] The Union of Kalmar broke apart in 1521 with the deposition of King Christian II of Denmark in Sweden; he was deposed again in Denmark-Norway eighteen months later.
[3] During the reformation in Denmark-Norway, 1536-1537, Holy Roman Emperor Charles V supported Frederick of Wittelsbach as king of Norway, in opposition against Christian III.
Under pressure from Charles V, he agreed to exempt the Dutch ships from these tolls and give them free and unfettered access to the Baltic.
[6] A secret clause in the treaty also pledged that Charles V would not support Christian II's heirs, including his daughters, Christina of Denmark and Dorothea of Denmark, wives of Duke Francis I of Lorraine and Frederick of Wittelsbach respectively, in the future.
An additional clause also declared that the King of Denmark-Norway would respect the rights of the Teutonic Order in return for Charles V's respect for Albrecht of Prussia - Albrecht was married to Christian III's sister, Dorothea, Duchess of Prussia.