In the period 1780-1787, the control of the Orangists and Patriots varied from place to place, and specifically in the area relevant to van der Palm, the Patriots held power in the city of Utrecht while the surrounding province was controlled by the Orangists. Civil war escalated in that period; but the climax arrived in September 1787 when the Prussian army invaded at the order of King Frederick William II of Prussia, allegedly as an angry response to the way his sister, Princess Wilhelmina of Prussia, wife of Prince William V, had been arrested by Patriots while on her way to the Hague to argue the case for her husband's reinstallment as Stadtholder. However, she had been released two days later, and the more likely reasons for King Frederick William's action were to assist the Orangists in opposing the Patriots and to restore Prince William to the Stadtholderate. Ultimately, Prussia was successful, many Patriots were driven into exile, and Prince William V was restored, briefly, as Stadtholder.