Blockade of StralsundStralsund, Germany
Sweden had entered the Seven Years' War in 1757, joining France, Russia, Austria and Saxony in their alliance against the Prussians. During Autumn 1757, with Prussian forces tied up elsewhere, the Swedes had been able to move south and occupy a large portion Pomerania. Following the retreat of the Russians from East Prussia, after the Battle of Gross-Jägersdorf, Frederick the Great ordered his General Hans von Lehwaldt to move west to Stettin to confront the Swedes. The Prussian troops proved to be better equipped and trained than the Swedes, and were soon able to push them back into Swedish Pomerania. The Prussians pressed home their advance, taking over Anklam and Demmin. The Swedes were left at the stronghold of Stralsund and the island of Rügen.
As Stralsund was not about to surrender it became apparent that the Prussians required naval support if they were to force it to yield. In light of this Frederick repeatedly requested that his British allies send a fleet into the Baltic Sea. Wary of being drawn into conflict with Sweden and Russia, with whom they were not at war, the British declined. They justified their decision by explaining their ships were needed elsewhere. The failure of Frederick to gain fleet support from the Royal Navy was a major factor in the failure of the Prussians to take Stralsund.