La muette de Portici
The Belgian Revolution broke out on 25 August 1830, after the performance of a nationalist opera ("La muette de Portici") in Brussels led to a minor insurrection among the capital's bourgeoisie, who sang patriotic songs and captured some public buildings in the city. This early revolutionary group was swelled by a large number of urban workers. The following day, the revolutionaries began flying their own flag, clearly influenced by that of the Brabant Revolution of 1789. To maintain order, several bourgeois militia groups were formed. The situation in Brussels led to widespread unrest across the country. William I rejected his son's advice to negotiate with the rebels, forcing them towards a more radical, pro-independence stance, and sent a large military force to Brussels suppress the insurrection.