War of the First Coalition The War of the First Coalition ( 1792 – 1797 ) was the first major effort of multiple European monarchies to contain Revolutionary France . France declared war on the Habsburg monarchy of Austria on 20 April 1792 , and the Kingdom of Prussia joined the Austrian side a few weeks later . These powers initiated a series of invasions of France by land and sea , with Prussia and Austria attacking from the Austrian Netherlands and the Rhine , and Great Britain supporting revolts in provincial France and laying siege to Toulon . France suffered reverses ( Battle of Neerwinden , 18 March 1793 ) and internal strife ( Revolt in the Vendée ) , and responded with extreme measures : the Committee of Public Safety formed ( 6 April 1793 ) and the " levée en masse " drafted all potential soldiers aged 18 to 25 ( August 1793 ) . The new French armies counter - attacked , repelled the invaders , and moved beyond France . French arms established the Batavian Republic as a satellite state ( May 1795 ) and gained the Prussian Rhineland by the first Treaty of Basel . With the Treaty of Campo Formio , the Holy Roman Empire ceded the Austrian Netherlands to France and Northern Italy was turned into several French " Sister Republics " . Spain made a separate peace accord with France ( second Treaty of Basel ) and the French Directory carried out plans to conquer more of Germany and northern Italy ( 1795 ) . North of the Alps , Archduke Charles of Austria redressed the situation in 1796 , but Napoleon carried all before him against Sardinia and Austria in northern Italy ( 1796 – 1797 ) near the Po Valley , culminating in the peace of Leoben and the Treaty of Campo Formio ( October 1797 ) . The First Coalition collapsed , leaving only Britain in the field fighting against France . Revolutionary violence in France . As early as 1791 , the other monarchies of Europe watched with alarm the developments in France , and considered whether they should intervene , either in support of Louis XVI or to take advantage of the chaos in France . The key figure was Holy Roman Emperor Leopold II , brother to the French Queen Marie Antoinette , who had initially looked on the Revolution with equanimity . He became more and more disturbed as the Revolution became more radical , although he still hoped to avoid war . On 27 August , Leopold and King Frederick William II of Prussia , in consultation with emigrant French nobles , issued the Declaration of Pilnitz , which declared the interest of the monarchs of Europe in the well - being of Louis and his family , and threatened vague but severe consequences if anything should befall them . Although Leopold saw the Pillnitz Declaration as a way of taking action that would enable him to avoid actually doing anything about France , at least for the moment , it was seen in France as a serious threat and was denounced by the revolutionary leaders . In addition to the ideological differences between France and the monarchical powers of Europe , there were continuing disputes over the status of Imperial estates in Alsace , and the French were becoming concerned about the agitation of emigré nobles abroad , especially in the Austrian Netherlands and the minor states of Germany . In the end , France declared war on Austria first , with the Assembly voting for war on 20 April 1792 , after the presentation of a long list of grievances by foreign minister Dumouriez . Early setbacks for France . Dumouriez prepared an immediate invasion of the Austrian Netherlands , where he expected the local population to rise against Austrian rule . However , the revolution had thoroughly disorganized the army , and the forces raised were insufficient for the invasion . The soldiers fled at the first sign of battle , deserting en masse and in one case , murdering Théobald Dillon their general . While the revolutionary government frantically raised fresh troops and reorganized its armies , an allied army under Charles William Ferdinand , Duke of Brunswick assembled at Koblenz on the Rhine . In July the invasion commenced with Brunswick ' s army , which was composed mostly of Prussian veterans . Brunswick was able to take the fortresses of Longwy and Verdun . The Duke then issued a declaration on 25 July , which had been written by the brothers of Louis XVI , that declared his [ Brunswick ' s ] intent to restore the King to his full powers and to treat any person or town who opposed them as rebels to be condemned to death by martial law . This motivated the revolutionary army and government to oppose them by any means necessary , and led almost immediately to the overthrow of the King by a crowd which stormed the Tuileries Palace . Tide turns in France ' s direction . The invaders continued , but at Valmy on 20 September , they came to a stalemate against Dumouriez and Kellermann in which the highly professional French artillery distinguished itself . Although the battle was a tactical draw , it gave a great boost to French morale . Further more , the Prussians , finding that the campaign had been longer and more costly than predicted , decided that the cost and risk of continued fighting was too great , and they decided to retreat from France to preserve their army . Meanwhile , the French had been successful on several other fronts , occupying Savoy and Nice in Italy , while General Custine invaded Germany , several German towns along the Rhine , and reaching as far as Frankfurt . Dumouriez went on the offensive in Belgium once again , winning a great victory over the Austrians at Jemappes on 6 November , and occupying the entire country by the beginning of winter . 1793 . On 21 January the revolutionary government executed Louis XVI after a trial . This united all Europe , including Spain , Naples , and the Netherlands against the revolution . France declared war against Britain and the Netherlands on 1 February 1793 and soon afterwards against Spain . In the course of the year 1793 the Empire , the kings of Portugal and Naples and the grand - duke of Tuscany declared war against France . Thus was formed the first coalition . France introduced a new levy of hundreds of thousands of men , beginning a French policy of using mass conscription to deploy more of its manpower than the other states could , and remaining on the offensive so that these mass armies could commandeer war material from the territory of their enemies . The French government sent Citizen Genet to the United States to encourage them into entering the war on France ' s side . George Washington , however , demanded he be sent back to France . 1794 . 1794 brought increased success to the revolutionary armies . Although an invasion of Piedmont failed , an invasion of Spain across the Pyrenees took San Sebastián , and the French won a victory at the Battle of Fleurus , occupying all of Belgium and the Rhineland . Action extended into the French colonies in the West Indies . A British fleet successfully captured Martinique , St . Lucia , and Guadeloupe , although a French fleet arrived later in the year and recovered the latter . 1795 . After seizing the Netherlands in a surprise winter attack , France established the Batavian Republic as a puppet state . Even before the close of 1794 the king of Prussia retired from any active part in the war , and on the 5 April 1795 he concluded with France the Peace of Basel , which recognized France ' s occupation of the left bank of the Rhine . The new French - dominated Dutch government purchased peace by surrendering Dutch territory to the south of that river . A treaty of peace between France and Spain followed in July . The grand duke of Tuscany had been admitted to terms in February . The coalition thus fell into ruin and France proper would be free from invasion for many years . Britain attempted to reinforce the rebels in the Vendée by landing French Royalist troops at Quiberon , but failed , and attempts to overthrow the government at Paris by force were foiled by the military garrison led by Napoleon Bonaparte , leading to the establishment of the Directory . On the Rhine frontier , General Pichegru , negotiating with the exiled Royalists , betrayed his army and forced the evacuation of Mannheim and the failure of the siege of Mainz by Jourdan . 1796 . The French prepared a great advance on three fronts , with Jourdan and Moreau on the Rhine , and Bonaparte in Italy . The three armies were to link up in Tyrol and march on Vienna . Jourdan and Moreau advanced rapidly into Germany , and Moreau had reached Bavaria and the edge of Tyrol by September , but Jourdan was defeated by Archduke Charles , and both armies were forced to retreat back across the Rhine . Napoleon , on the other hand , was completely successful in a daring invasion of Italy . He separated the armies of Sardinia and Austria , defeating each one in turn , and then forced a peace on Sardinia while capturing Milan and besieging Mantua . He defeated successive Austrian armies sent against him under Wurmser and Alvintzy while continuing the siege . The rebellion in the Vendée was also finally crushed in 1796 by Hoche , but Hoche ' s attempt to land a large invasion force in Ireland was unsuccessful . 1797 . On 2 February Napoleon finally captured Mantua , with the Austrians surrendering 18 , 000 men . Archduke Charles of Austria was unable to stop Napoleon from invading the Tyrol , and the Austrian government sued for peace in April . At the same time there was a new French invasion of Germany under Moreau and Hoche . On 22 February French invasion force consisting of 1 , 400 troops from the " La Legion Noire " ( The Black Legion ) under the command of Irish American Colonel William Tate landed near Fishguard ( Wales ) . They were met by a quickly assembled group of around 500 British reservists , militia and sailors under the command of John Campbell , 1st Baron Cawdor . After brief clashes with the local civilian population and Lord Cawdor ' s forces on 23 February , Tate was forced into an unconditional surrender by 24 February . Austria signed the Treaty of Campo Formio in October , ceding Belgium to France and recognizing French control of the Rhineland and much of Italy . The ancient Republic of Venice was partitioned between Austria and France . This ended the War of the First Coalition , although Great Britain and France remained at war .