On the outbreak of the insurrection at Brussels in August 1830, Rogier went there with a militia of about 300 citizens from Liège. In Brussels he gained recognition as one of the most active among the patriot leaders, and his influence saved the town hall from pillage on 19 September. Five days later a was formed, of which Rogier became president. The measures of this body and of its successor, the , soon freed the greater part of the country from the Dutch troops. In October Rogier was also sent to suppress an outbreak among the colliers of Hainaut Province.
