The direct cause was the Arrest at Goejanverwellesluis (actually Bonrepas) of Stadtholder William V of Orange's wife, Wilhelmina of Prussia, on 28 June 1787. She was on her way from Nijmegen, where William V had taken refuge, to The Hague, where she intended to request her husband to be allowed to return to, after the States of Holland had fired him as Captain General of their troops in 1786.This had not been done on a whim: the decision to travel to The Hague had only been taken after Gijsbert Karel van Hogendorp had undertaken a secret mission to the Orangist leaders in that city to discuss its advisability, because her husband was, as usual, hesitating about what course of action to follow. The leader of the Orangist party in The Hague, the British envoy James Harris saw possibilities to put pressure on the States of Holland if the Princess suddenly arrived, and he told van Hogendorp to give the green light to the Princess, who was with her husband in the armed camp of the Dutch States Army in Amersfoort. The stadtholder then grudgingly gave his consent.
The Princess then returned to Nijmegen, while preparations for the journey to The Hague were made by ordering fresh horses for her carriages along the route in two places. This caused suspicion among the Patriot Free Corps in the area, who in this way were alerted to her supposedly secret travel plans. The military authorities posted Free Corps patrols in the affected area with orders to intercept her. When on 28 June 1798 she departed from Nijmegen to The Hague with a small retinue (a chamberlain, a lady in waiting, and two officers, colonel Rudolph Bentinck, an adjutant of the stadtholder, and Frederick Stamford, the military tutor of her sons), but no armed escort (Harris had advised it was safe enough to only take a bag of gold along to bribe Patriot Free Corps with) she was indeed intercepted near Goejanverwellesluis by a Free Corps patrol from Gouda. She was not mistreated, as has been asserted by Orangist propagandists, but only temporarily detained in a nearby farm, to await the arrival of members of the Military Commission in Woerden. The only untoward thing that happened was that the leader of the patrol drew his saber, but he put it back in its scabbard when requested. When the Military Commission arrived she was told she would not be allowed to proceed to The Hague, for fear of instigating public unrest there, but she was immediately released, and allowed to return to Nijmegen.