near the Goejanverwellesluis in the hamlet of Bonrepas. The Princess was not harmed and she was soon allowed to return to Nijmegen, but the fact that her captors had been impolite (one of them sat unbidden at her dinner table, which was a serious breach of etiquette; another stood with a drawn sabre in her presence) caused great consternation and outrage. Especially her brother the Prussian king now lost his patience with the Patriots, and the Dutch in general, and demanded in a first ultimatum to the States General the immediate reinstatement of the Princess in The Hague, and the exemplary punishment of the culprits of the . The States of Holland were less than impressed and urged that the ultimatum would be huffily ignored. Now the French played a dangerous game. Vergennes' successor Montmorin gave the impression that France would support the Patriots in case of Prussian military intervention and that to this end a military camp was being prepared in Givet, on an invasion route through the independent Prince-Bishopric of Liège, obviating the necessity of entering the Austrian Netherlands. This turned out to be a bluff, and once this became clear to the Prussians and Harris, nothing prevented an invasion of the Republic. But the Patriots, informed of the French intervention plans by yet another French envoy Jean-François de Bourgoing believed in the Givet camp till it was too late, and it steeped them in their resistance to the Prussian demands. An invasion force of around 26,000 Prussian troops under the command of the duke of Brunswick (a nephew of William's old mentor) entered the Republic on 13 September 1787, after a final ultimatum was again left unanswered. Despite all the martiality of the Free Corps their resistance proved to be negligible. The armed camp of Utrecht, where the Rhinegrave of Salm had personally assumed command a few months earlier, was evacuated without a fight, after Salm on 14 September convinced the Military Commission in Woerden that it was a rat trap, about to be encircled by two Prussian pincers, and that it was strategically necessary to retreat to Amsterdam. This earned the Rhinegrave the enduring opprobrium of the Patriots and all Dutch historians, but he was probably right. The retreat proved, however, a death blow to Patriot morale. Though the Patriots indeed made a stand around Amsterdam (without Salm, however, who was replaced by a French officer,