Shortly afterward a constitutional crisis erupted in the States General. These were equally divided between three Orangist provinces (Zeeland, Gelderland and Friesland) and three Patriot provinces (Holland, Groningen and Overijssel), while Utrecht was leaning Orangist, and held the balance. In June 1787 the rival Patriot States of Utrecht demanded to be seated in the States General, supported by the three Patriot provincial delegations. Patriot Overijssel temporarily presided at the time, and provisionally seated the Patriot States. This led to riotous behavior by the delegation of the Amersfoort States of Utrecht, one of whose members, drew his sword in the meeting hall, and challenged d'Averhoult, who was a member of the rival Patriot delegation, to a duel. This may or may not have been held the next day in the Hague Wood, fortunately with only slight damage to the participants. The Amersfoort delegation was eventually restored to its position of sole representative of Utrecht in the States General, giving the majority to the Orangists. This was one of the proximate causes of the Prussian invasion of Holland That invasion met little resistance from the Patriots, though d'Averhoult again distinguished himself by repelling several Prussian attacks near fort Nieuwersluis, before his troops were overwhelmed, and he was made a prisoner of war. The Prussians treated him respectfully and he was released and allowed to join the Patriot exodus to Brussels, together with his aunt Josina d'Averhoult.