The French Revolutionary Wars began on 20 April 1792 when the French Legislative Assembly declared war on Austria. This launched the War of the First Coalition.
Background
From 1789 to early 1792, the French Revolution gradually radicalised, breaking with old institutions and practices as it went, and targeting defenders of the Ancien Régime. Some of these defenders, or people who were unintentionally caught in the crossfire, emigrated from France to avoid persecution. King Louis XVI himself attempted to escape with his family to Varennes in June 1791, but he was caught. The French king was put under surveillance, and increasingly suspected of conspiring with other European monarchs, who wished to preserve the House of Bourbon in France and restore its pre-revolutionary authority. This was explicitly stated in the Declaration of Pillnitz (17 August 1791) by king Frederick William II of Prussia and emperor Francis II (Austria, Hungary and Bohemia), who called on all monarchs in Europe to 'liberate' Louis.Encarta-encyclopedie Winkler Prins (1993–2002) s.v. "Pillnitz, Conferentie van". Microsoft Corporation/Het Spectrum. Leading radical revolutionaries called for the complete abolition of the monarchy, but the republican movement was dealt a severe blow in the July 1791 Champs de Mars Massacre.Encarta-encyclopedie Winkler Prins (1993–2002) s.v. "Franse Revolutie. §1.1 Eerste periode". Although this cleared the way for the establishment of the constitutional monarchy in September, it did not secure Louis XVI's position. The uncertain future of the Bourbon monarchy caused tensions to rise between France and other European states.
In early 1792, conservative royalist Armées des Émigrés were forming just across the borders in cities such as Koblenz, readying themselves to invade and end the Revolution with the help of other monarchies. The Girondin majority in the Legislative Assembly favoured war, especially with Austria, in order to display the Revolution's strength and defend its achievements (such as the Declaration of the Rights of the Man and of the Citizen of 1789 and the early beginnings of parliamentary democracy) against a possible return to an (Enlightened) absolutist regime.Encarta-encyclopedie Winkler Prins (1993–2002) s.v. "girondijnen". Microsoft Corporation/Het Spectrum. They cited the Declaration of Pillnitz to justify the urgent need to strike first. Many of the French revolutionaries wanted to spread their Revolution to other countries, and refugees from recently failed revolutions, such as Dutch Patriots and Belgian-Liégois rebels, urged their French comrades to 'liberate' the Low Countries.Encarta-encyclopedie Winkler Prins (1993–2002) s.v. "Bataafse Republiek. §1. Ontstaan"; "Brabantse Omwenteling. §4. De mislukking van de Verenigde Belgische Staten ". Microsoft Corporation/Het Spectrum. However, there was a real risk that France would be overwhelmed by foreign forces if a large anti-French coalition were to be formed. This is why many leftist deputies within the Assembly such as Robespierre opposed a war,Encarta-encyclopedie Winkler Prins (1993–2002) s.v. "Robespierre, Maximilien de". Microsoft Corporation/Het Spectrum. arguing France was not ready for it and could lose all progress (as they saw it) made thus far during the Revolution.
Preparations Diplomacy
Major-general Charles François Dumouriez was appointed Minister of Foreign Affairs in March 1792, and by mid-April had managed to obtain the neutrality of all European great powers except Austria and Prussia through diplomacy. Meanwhile, he organised plans to incite a rebellion in the Austrian Netherlands by cooperating with the Committee of United Belgians and Liégeois, who represented remnants of the rebel armies formed during the recently failed anti-Austrian Brabant Revolution and Liège Revolution (August 1789 – January 1791).
Strategy Finally, France declared war on Austria on 20 April 1792. Dumouriez planned to defeat the Austrian army within 15 days to achieve a successful quick victory. From Dunkirk to Strasbourg, the French northern frontier comprised 164,000 soldiers, divided into three armies under the leadership of general Lafayette (Armée du Centre;Connelly, p. 23. targets: from Givet to Namur and Liège), marshal Luckner (Armée du Rhin; targets: Flemish cities such as Menen and Kortrijk) and marshal Rochambeau (Armée du Nord; targets: Quiévrain, Mons and Brussels).
The invasion heavily relied on the presumption that Belgian and Liégois patriotic rebellions would break out spontaneously the moment French troops crossed the border, aiding them in driving out the Habsburg forces as they had done themselves 2.5 years before. Dumouriez assured his fellow ministers:Howe, p. 70.
As soon as the French army enters the Belgian provinces, it will be helped by the people, who are ashamed of their own futile revolutionary efforts of [1789–1790]. They will join forces with our troops and will easily drive the dispersed hordes of Austrian mercenaries from their towns or scatter them. Paris will be defended on the banks of the Meuse. For the Country of Liège, the one most worthy of freedom of all those who have raised its flag, our negotiators will depart to dictate a wise peace, which we will under no circumstances spoil by the spirit of conquest.
State of the French military The French army was plagued by troubles: leading generals such as Lafayette and Rochambeau were moderate royalists, and had doubts about the republican minister's intentions as well as the feasibility of his strategies; the troops were poorly equipped, many of them untrained volunteers, and they distrusted their aristocratic officers; and finally, queen Marie Antoinette, who was Austrian and feared further republican radicalisation would result in her execution, secretly passed war plans to the Austrian government in Brussels, with Louis XVI's approval. Moreover, Prussia soon joined Austria against France, later followed by other powers and the armies of émigrés, while the ferment of the Revolution caused political instability, and want of materiel and funds left France's armed forces disorganised.
More than 50% of the army's officers, which consisted solely of noblemen, had fled the country in the past three years of revolutionary upheaval. It took time to replace these by non-commissioned officers and volunteers from the middle class. There was also animosity between the old regulars (the "whites", from their uniform) and the new soldiers who joined the army as volunteers in 1791–2 (the so-called "blues"). And because of the revolutionary egalitarian ideas penetrating the ranks of the military, there was distrust against the remaining noble officers; their loyalty to the cause of the Revolution and their orders were questioned.
One lasting morale-boosting effect was the composition of the battle hymn Chant de guerre pour l'armée du Rhin ("War Song for the Rhine Army") by Rouget de Lisle in April 1792. It became popular among French soldiers nationwide, and was soon identified with a battalion from Marseille. Thus, the song became known as La Marseillaise, and on 26 Messidor III (14 July 1795) and again on 14 February 1879 it was officially recognised as the national anthem of France.Encarta-encyclopedie Winkler Prins (1993–2002) s.v. "Marseillaise, La". Microsoft Corporation/Het Spectrum.
Belgian front April: first French invasion
Despite protesting that the army was not in condition to fight, Rochambeau obeyed his orders. He departed Paris and moved towards Valenciennes on 21 April to assume command of the northern army, and make final preparations for the invasion. Rochambeau's subordinate general Biron and maréchal du camp Théobald Dillon would lead the invasion.
The French national anthem, La Marseillaise, was composed in Strasbourg, April 25, while the French were still mustering troops, as the "Chant de guerre pour l'Armée du Rhin" ("War Song for the Army of the Rhine").
The French army performed poorly in the first engagements. At the Battle of Marquain near Tournai (29 April), French soldiers fled almost at first sight of the Austrian outposts and murdered their general Théobald Dillon, whom they accused of treason. Meanwhile, general Biron suffered a defeat at Quiévrain near Mons. On 30 April, the Dunkirk column marched 15 miles to Veurne, but encountered no enemy and retreated back to Dunkirk.
When both his subordinates Dillon and Biron failed in their missions, Rochambeau resigned. On 30 April, Lafayette heard of the defeats and Rochambeau's resignation, cancelled his assault on Namur and Liège as well and awaited new orders from Paris. The Belgian-Liègeois Committee was disappointed and felt betrayed, claiming Lafayette could have easily taken both cities by sheer superior numbers.
May: French troops regroup The commanders-in-chief of the armies became political "suspects"; and before a serious action had been fought, the three armies commanded respectively by Rochambeau, Lafayette and Luckner had been reorganised into two commanded by Dumouriez and Kellermann.
June: second French invasion On 9 June, a 20,000 strong force commanded by Luckner invaded the Austrian Netherlands again, this time capturing Menen and Kortrijk (19 June). The Austrian troops under Johann Peter Beaulieu counter-attacked, however, blocking further advance. The French withdrew back to Lille on 30 June, effectively putting an end to their second northward incursion.Connelly, p. 24.
Rhine front July: allies rally and issue Brunswick Manifesto On the Rhine, a combined army of Prussians, Austrians, Hessians and French émigrés under the Duke of Brunswick was formed for the invasion of France, flanked by two smaller armies on its right and left, all three being under the supreme command of King Frederick William II of Prussia. In the Southern Netherlands, plans called for the Austrians to besiege Lille, and in the south the Piedmontese also took the field. Observing the enemy coalition gathering at its borders, the Assembly declared the 'nation in danger', and commanded 100,000 National Guards (Fédérés) to strengthen the defence of Paris; the king vetoed the decision, but he was ignored.Connelly, p. 25.
The first step was the issue of the Brunswick Manifesto (25 July), a proclamation which, couched in terms most insulting to the French nation, generated the spirit that was afterwards to find expression in the "armed nation" of 1793–1794, and sealed the fate of King Louis XVI. It was issued against the advice of Brunswick himself, whose signature appeared on it; the duke, a model sovereign in his own principality, sympathised with the constitutional side of the French Revolution, while as a soldier he had no confidence in the success of the enterprise. Brunswick stressed that civilians would not be harmed or looted, unless they harmed the royal family: "If the least violence, the least outrage, be done to their majesties... [my troops] will take... unforgettable vengeance [on] the city of Paris...". The Brunswick Manifesto reached Paris on 1 August and was posted in numerous places across the capital, and received much hostility and mockery. Instead of intimidating the Parisians, it confirmed their determinacy to oppose any foreign invasion, and to get rid of the royals who were increasingly, and with ever more evidence, suspected of treason against the Revolution, the Assembly and the French people.
10 August: storming of the Tuileries