The Treaty of Muenster (1648) had left the Dutch in possession of territory on both banks of the Scheldt, and had given them the right to close all access by river to Antwerp, which had for a century and a quarter ceased to be a sea-port.  In 1781, during his visit to Belgium, Joseph had received a number of petitions in favour of the liberation of the Scheldt.  At the moment he did not see his way to taking action, but in 1783 he took advantage of the embarrassments of the Dutch government to raise the question of a disputed boundary in Dutch Flanders; and in the autumn of that year a body of Imperial troops took forcible possession of some frontier forts near Sluis.  Matters were brought to a head in May, 1784, by the emperor sending to the States-General a detailed summary of all his grievances, Tableau sommaire des pretentions.  In this he claimed, besides cessions of territory at Maestricht and in Dutch Flanders, the right of free navigation on the Scheldt, the demolition of the Dutch forts closing the river, and freedom of trading from the Belgian ports to the Indies.  This document was in fact an ultimatum, the rejection of which meant war.  For once all parties in the Republic were united in resistance to the emperor’s demands; and when in October, 1784, two ships attempted to navigate the Scheldt, the one starting from Antwerp, the other from Ostend, they were both stopped; the first at Saftingen on the frontier, the second at Flushing.  War seemed imminent.  An Austrian army corps was sent to the Netherlands; and the Dutch bestirred themselves with a vigour unknown in the States for many years to equip a strong fleet and raise troops to repel invasion.  It is, however, almost certain that, had Joseph carried out his threat of sending a force of 80,000 men to avenge the insult offered to his ships, the hastily enlisted Dutch troops would not have been able to offer effectual resistance.  But the question the emperor was raising was no mere local question.  He was really seeking to violate important clauses of two international treaties, to which all the great powers were parties, the Treaty of Muenster and the Treaty of Utrecht.  His own possession of the Belgian Netherlands and the independence and sovereign rights of the Dutch Republic rested on the same title.  Joseph had counted upon the help or at least the friendly neutrality of his brother-in-law, Louis XVI, but France had just concluded an exhausting war in which the United Provinces had been her allies.  The French, moreover, had no desire to see the Republic over-powered by an act of aggression that might give rise to European complications.  Louis XVI offered mediation, and it was accepted.