mostly ignored, Louis XVI was later able to find support in Leopold II of Austria (brother of Marie Antoinette) and Frederick William II of Prussia. On 27 August 1791, these foreign leaders made the Pillnitz Declaration, saying they would restore the French monarch if other European rulers joined. In response to what they viewed to be the meddling of foreign powers, France declared war on 20 April 1792. However, at this point, the war was only Prussia and Austria against France. France began this war with a series of major defeats, which set a precedent of fear of invasion in the people that would last throughout the war. Massive reforms of military institutions, while very effective in the long run, presented the initial problems of inexperienced forces and leaders of questionable political loyalty. In the time it took for officers of merit to use their new freedoms to climb the chain of command, France suffered. Many of the early battles were definitive losses for the French. There was the constant threat of the Austro-Prussian forces which were advancing easily toward the capital, threatening to destroy Paris if the monarch was harmed. This series of defeats, coupled with militant uprisings and protests within the borders of France, pushed the government to resort to drastic measures to ensure the loyalty of every citizen, not only to France but more importantly to the Revolution. While this series of losses was eventually broken, the reality of what might have happened if they persisted hung over France. The tide would not turn from them until September 1792 when the French won a critical victory at Valmy preventing the Austro-Prussian invasion. While the French military had stabilized and was producing victories by the time the Reign of Terror officially began, the pressure to succeed in this international struggle acted as justification for the government to pursue its actions. It was not until after the execution of Louis XVI and the annexation of the Rhineland that the other monarchies began to feel threatened enough to form the First Coalition. The Coalition, consisting of Russia, Austria, Prussia, Spain, Holland, and Sardinia began attacking France from all directions, besieging and capturing ports and retaking ground lost to France. With so many similarities to the first days of the Revolutionary Wars for the French government, with threats on all sides, unification of the country became a top priority. As the