The authorities permitted, on the evening of the 25th, the first performance of an opera by Scribe and Auber, entitled La Muette de Portici, which had been previously proscribed.
The hero, Masaniello, headed a revolt at Naples in 1648 against foreign (Spanish) rule. The piece was full of patriotic, revolutionary songs likely to arouse popular passion.
The evening of the performance arrived, and the theatre was crowded. The excitement of the audience grew as the play proceeded; and the thunders of applause were taken up by the throng which had gathered outside. Finally the spectators rushed out with loud cries of vengeance against Libri-Bagnano and Van Maanen, in which the mob eagerly joined. Brussels was at that time a chosen shelter of political refugees, ready for any excesses; and a terrible riot ensued. The house of Van Maanen and the offices of the National were attacked, pillaged and burnt. The city was given over to wild confusion and anarchy; and many of the mob secured arms by the plunder of the gun-smiths’ shops. Meanwhile the military authorities delayed action. Several small patrols were surrounded and compelled to surrender, while the main body of troops, instead of attacking and dispersing the rioters, was withdrawn and stationed in front of the royal palace. Thus by the extraordinary passiveness of Lieut.-General Bylandt, the military governor of the province, and of Major-General Wauthier, commandant of the city, who must have been acting under secret orders, the wild outbreak of the night began, as the next day progressed and the troops were still inactive, to assume more of the character of a revolution.
In 1830, the harvest failed and provisioning became tight. When the revolution in Paris started in July 1830, the unrest spread to the lower classes in Belgium. After the performance of the opera, 'La Muette de Portici', on 25 August 1830, proletarian riots occurred in Brussels. The citizens of Brussels wanted to defend themselves against these riots, and established the citizens’ militia. On 1 September, the leaders of this militia asked William of Orange, son and successor to William I, who was camped in Vilvoorde, to mediate with his father on the administrative separation of the North and the South. William I felt he was being blackmailed and refused to give in.
Catholic partisans watched with excitement the unfolding of the July Revolution in France, details of which were swiftly reported in the newspapers. On 25 August 1830, at the Théâtre Royal de la Monnaie in Brussels, an uprising followed a special performance (in honor of William I's birthday) of Daniel Auber's La Muette de Portici (The Mute Girl of Portici), a sentimental and patriotic opera suited to fire National Romanticism, for it was set against Masaniello's uprising against the Spanish masters of Naples in the 17th century. The duet, "Amour sacré de la patrie", (Sacred love of Fatherland) with Adolphe Nourrit in the tenor role, engendered a riot that became the spark for the Belgian Revolution. The crowd poured into the streets after the performance, shouting patriotic slogans, and swiftly took possession of government buildings. The coming days saw an explosion of the desperate and exasperated proletariat of Brussels.