1830 and the causes (see link).
On August 25th. 1830 a performance of the opera, The Mute Girl of Portici,
took place at the Théâtre de la Monnaie in Brussels.
The opera evoked sentimental and nationalist feelings.
On this link you can listen to a piece of the opera.
|Théàtre de la Monnaie in Brussels|
with William (Willem in Dutch) I as King.
After the opera riots broke out in Brussels. This marked the start of the
Only in 1831 Belgium had a new King: Leopold I of Saxe-Coburg and Gotha