The chancellor and head of the Caps party, baron Anders Johan von Höpken, sent an army of 14,500 men to Stralsund, capital of Swedish Pomerania, under field-marshal Ungern-Sternberg, with his main mission being the capture of Stettin (today in Poland), which controls the mouths of the Oder.

Although Prussian troops in the area had been heavily denuded to face the Russian threat, they put up a tenacious resistance to the Swedes and battles and skirmishes came one after the other without either of the belligerents able to gain a decisive advantage over the other.

The conflict took a naval turn when the Prussians built a fleet at Stettin, by the more or less fortunate transformation of fishing or transport boats into warships, to defy a Swedish squadron supporting their land offensive.

The Battle of Frisches Haff was thus a short-lived victory for the Swedes and the Russian retreat from the war of 1762 placed them in a very difficult situation.

Realising they did not have a large enough force to hold off the redoubtable troops under king Frederick II of Prussia on their own, the Swedes proposed a peace settlement to him based on a return to the pre-war status quo.