While campaigning against the French for control of Alsace in 1674, most of Frederick William's army went into winter quarters in Franconian Schweinfurt. As viceroy ("Statthalter"), John George commanded the troops remaining in Brandenburg. King Louis XIV of France convinced King Charles XI of Sweden to invade Brandenburg; after dispersing John George's small force, the Swedish troops went into winter quarters as well. The Prince of Dessau took part in Frederick William's retaliatory campaign in 1675, which resulted in the Battle of Fehrbellin.