France Declares War on Austria

Background. Relations between French revolutionaries and neighboring monarchies deteriorated after the Declaration of Pillnitz in August 1791. European monarchs, including Leopold and Frederick William II, expressed concern for Louis XVI and threatened consequences if he was harmed. This diplomatic tension created a volatile environment where intervention was considered by various powers, setting the stage for the formal declaration of war by France.

Declaration of War. On 20 April 1792, the revolutionary-led Legislative Assembly voted to declare war on Austria. This decision followed the presentation of a long list of grievances by newly appointed foreign minister Charles François Dumouriez. Dumouriez sought a war that might restore popularity and authority to the King. Prussia, having allied with Austria in February, declared war on France in June 1792.

Initial Conflict. In July 1792, an army under the Duke of Brunswick, composed mostly of Prussians, joined the Austrian side and invaded France. The Duke issued a declaration on 25 July 1792, written by the brothers of Louis XVI, stating his intent to restore the King to full powers. This declaration threatened martial law against those opposing him, escalating the conflict.