Charles X of Sweden had concluded the earlier war with Denmark with a stunning victory by succeeding in the bold March across the Belts. Denmark-Norway had been forced into a humiliating peace in the Treaty of Roskilde in which Denmark had to cede Scania, Halland and Blekinge on the Scandinavian Peninsula and the island of Bornholm, and Norway lost the provinces of Båhuslen and Trøndelag. Europe was stunned by the quick victory, and Charles proudly publicized his accomplishments. However, peace meant new problems. In the peace treaty of Roskilde, Denmark was obliged to supply the Swedish army with provisions until May 1658, but soon thereafter the army would need to be moved. The Swedish king knew that the army would not be able to be supplied in Sweden for long, and disbanding it was not desirable with the Poles eager to revenge the 1655 invasion of Poland-Lithuania. Sweden was not in want of enemies to attack: campaigns in Livonia and Estonia were considered, but were rejected due to supply problems. The Swedish King maintained that his main goal was to invade Royal Prussia, but he also wanted to punish Frederick William of Brandenburg-Prussia. The many enemies in continental Europe, among them Poland and a hostile Dutch would make this a difficult endeavor however. A new attack on Prussia would also see little international support, France was already urging peace. The surprising Swedish solution to this dilemma would be to return to Denmark in an attempt to finish the job.