With the dissolution of the Legislative Assembly in October 1791, Custine was appointed lieutenant general to the Army of the Vosges, as the army of volunteers was known. Despite his strict discipline, he was popular with the soldiers, amongst whom he was known as "général moustache". The following year he was appointed commander-in-chief of the army, replacing Nicolas Luckner; in the following campaign, he took Speyer, Worms, Mainz and Frankfurt in September and October 1792.