Margraviate of Brandenburg fief of the Polish–Lithuanian Commonwealth, to which the electors paid homage. The electors of Brandenburg spent the next two centuries attempting to gain lands to unite their separate territories (the Mark Brandenburg, the territories in the Rhineland and Westphalia, and Ducal Prussia) to form one geographically contiguous domain. In the Peace of Westphalia ending the Thirty Years' War in 1648, Brandenburg-Prussia acquired Farther Pomerania and made it the Province of Pomerania by the Treaty of Stettin (1653). In the second half of the 17th century, Frederick William, the "Great Elector", developed Brandenburg-Prussia into a major power. The state constructed Brandenburg's
Dominions of Sweden Norway to the king of Sweden under the Treaty of Kiel, which followed on Second War against Napoleon. However the treaty of Kiel never came into force: instead sovereignty of Western Pomerania passed to Kingdom of Prussia, who already held the eastern parts and merged them into the Province of Pomerania. Norway declared her independence, but was forced after a short war into a personal Union with Sweden. Sweden received the German town of Wismar with the surrounding countryside in the Peace of Westphalia (1648). In 1803 Wismar was pawned, in exchange for a loan, and control was handed over