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
Kettle War the economy of the northern Netherlands (namely Amsterdam), but the southern cities were dislodged from their important trading position. The closure of the Scheldt was confirmed by the Peace of Westphalia in 1648, to which the Spanish agreed. After the War of the Spanish Succession, the Spanish Netherlands had been ceded to Austria by the Treaty of Rastatt in 1714. Since Europe's "Diplomatic Revolution" of 1756, Austria, and thus the Austrian Netherlands, had been in an alliance with France. Prussia, France's former ally, entered into an alliance with Britain. The change, sensational at the time, made nonsense of all the