But soon the Dutch would have occasion to come to the aid of the Danes in a conflict with Sweden. In 1654 Charles X Gustav of Sweden ascended the Swedish throne and he embarked on an aggressive policy, in the process harming Dutch interests in several ways. He blockaded the port of Danzig during the Polish part of the Northern Wars, hindering Dutch commerce. In July, 1656 Cornelis de Graeff sent a fleet under Jacob van Wassenaer Obdam of the new Dutch navy. The fleet was dispatched to Danzig which helped persuade the Swedes to lift this blockade. Obdam was the commander-in-chief of the Dutch navy in these years, a political appointment by De Witt, who preferred an officer of the right political color to be in charge, in preference to more competent, but politically undesirable Orangists, when Witte Corneliszoon de With and Michiel de Ruyter (both States-Party men) were unavailable for different reasons. As Obdam was basically a landlubber, this was not an ideal solution, but in this context he proved up to the job.