Explanation : (because somebody has to do it.)

https://en.wikipedia.org/wiki/Belgian_Revolution

"The Belgian Revolution was a conflict which led to the secession of the southern provinces (mainly the former Southern Netherlands) from the United Kingdom of the Netherlands and the establishment of an independent Kingdom of Belgium.

The people of the south were mainly Flemings and Walloons. Both peoples were traditionally Catholic as contrasted with Protestant-dominated (Dutch Reformed) people of the north. Many outspoken liberals regarded King William I’s rule as despotic. There were high levels of unemployment and industrial unrest among the working classes.

On 25 August 1830, riots erupted in Brussels and shops were looted. Theatregoers who had just watched the nationalistic opera La muette de Portici joined the mob. Uprisings followed elsewhere in the country. Factories were occupied and machinery destroyed. Order was restored briefly after William committed troops to the Southern Provinces but rioting continued and leadership was taken up by radicals, who started talking of secession."

About the opéra :

https://en.wikipedia.org/wiki/La_muette_de_Portici

“The opera is loosely based on the historical uprising of Masaniello against Spanish rule in Naples in 1647.”