How did the Thirty Years’ War affect Brandenburg before Frederick William became elector?

Before Frederick William became elector in 1640, Brandenburg suffered significantly during the Thirty Years’ War. Although the electorate initially sought to maintain neutrality, it was unable to avoid the conflict's devastating impact.1

The region endured repeated invasions and long-term occupation by Swedish forces. By the time Frederick William succeeded his father, George William, he inherited a ravaged land that remained occupied by foreign troops. Under the influence of George William’s advisor, Graf Adam von Schwarzenberg, Brandenburg had also shifted its allegiance between the Habsburgs and the Swedes, which resulted in the territory being drawn into the struggle on both sides.12