Meanwhile at Brussels, owing to the inaction of the government, matters were moving fast.  The spirit of revolt had spread to other towns, principally in the Walloon provinces.  Liege and Louvain were the first to move.  Charles Rogier, an advocate by profession and a Frenchman by birth, was the leader of the revolt at Liege; and such was his fiery ardour that at the head of some 400 men, whom he had supplied with arms from the armourer’s warehouses, he marched to Brussels, and arrived in that disturbed city without encountering any Dutch force.  The example of Liege was followed by Jemappes, Wavre, and by the miners of the Borinage; and Brussels was filled with a growing crowd of men filled with a revolutionary spirit.  Their aim was to proclaim the independence of Belgium, and set up a provisional government.

For such a step even pronounced liberals like Gendebien, Van de Weyer and Rouppe, the veteran burgomaster of the city, were not yet prepared; and they combined with the moderates, Count Felix de Merode and Ferdinand Meeus, to form a Committee of Public Safety.  They were aided, in the maintenance of order, by the two Barons D’Hoogvoort (Emmanuel and Joseph), the first the commander of the civic guard, and both popular and influential, and by the municipality.  While these were still struggling to maintain their authority, the States-General had met at the Hague on September 13.  It was opened by a speech from the king which announced his firm determination to maintain law and order in the face of revolutionary violence.  He had submitted two questions to the consideration of the States-General:  (1) whether experience had shown the necessity for a modification of the Fundamental Law; (2) whether any change should be made in the relations between the two parts of the kingdom.  Both questions were, after long debate (September 29) answered in the affirmative; but, before this took place, events at Brussels had already rendered deliberations at the Hague futile and useless.

The contents of the king’s speech were no sooner known in Brussels than they were used by the revolutionary leaders to stir up the passions of the mob by inflammatory harangues.  Rogier and Ducpetiaux, at the head of the Liegeois and the contingents from the other Walloon towns, with the support of the lowest elements of the Brussels population, demanded the dissolution of the Committee of Public Safety and the establishment of a Provisional Government.  The members of the Committee and of the Municipality, sitting in permanence at the Hotel de Ville, did their utmost to maintain order with the strong support of Baron D’Hoogvoort and the Civic Guard.  But it was in vain.  On the evening of September 20 an immense mob rushed the Hotel de Ville, after disarming the Civic Guard; and Rogier and Ducpetiaux were henceforth masters of the city.  The Committee of Public Safety disappeared and is heard of no more.  Hoogvoort resigned his command.  On receipt of this news Prince Frederick at Vilvoorde was ordered to advance upon the city and compel submission.  But the passions of the crowd had been aroused, and the mere rumour that the Dutch troops were moving caused the most vigorous steps to be taken to resist a outrance their penetrating into the town.