The Army of the Danube () was a field army of the French Directory in the 1799 southwestern campaign in the Upper Danube valley. It was formed on 2 March 1799 by the simple expedient of renaming the Army of Observation, which had been observing Austrian movements on the border between French First Republic and the Holy Roman Empire. It was commanded by General Jean-Baptiste Jourdan, 1st Comte Jourdan (1762–1833).
The formation of the army was part of the French Directory's long term strategy to undermine Habsburg influence in the Holy Roman Empire, and, conversely, to strengthen French hegemony in central Europe after the wars of the First Coalition and the Treaty of Campo Formio in 1797. Despite the Treaty, Austria and France remained suspicious of each other's motives, and the purpose of the Army of the Observation was to watch for Austrian border transgressions. Understanding that the negotiations at the Congress of Rastatt were going no-where, the Army of Observation was instructed to cross the Rhine. Once across the Rhine, the Army of the Danube, was to secure strategic positions in southwestern Germany (present day Baden-Württemberg) and engage Archduke Charles' Habsburg army. In the meantime, the Army of Helvetia, under command of André Masséna, would secure such strategic locations as St. Gotthard Pass, the Swiss Plateau, and upper Rhine basin.
The army participated in four battles. In the battles of Ostrach and first Stockach, the Army of the Danube withdrew after suffering heavy losses. After reorganization, in which elements of the army were combined with Massena's Army of Switzerland, it withdrew after an engagement with Charles' superior force at Zürich in early June 1799; only in the Second Battle of Zurich did the Army of the Danube secure an uncontested victory. In December 1799, the Army of the Danube merged with the Army of the Rhine.
Background
Initially, such rulers of Europe as Joseph II, Holy Roman Emperor viewed the revolution in France as an event between the French king and his subjects, and not something in which they should interfere. As the rhetoric grew more strident, the monarchies started to view events with distrust. Leopold, who had succeeded Joseph as Emperor in 1791, saw the situation surrounding his sister, Marie Antoinette, and her children, with greater and greater alarm. As the revolution grew more and more radical, he still sought to avoid war, but in the late summer, he, in consultation with French émigré nobles and Frederick William II of Prussia, issued the Declaration of Pillnitz, in which they declared the interest of the monarchs of Europe as one with the interests of Louis and his family. They threatened vague, but serious, consequences if anything should happen to the royal family.Timothy Blanning. The French Revolutionary Wars, New York: Oxford University Press, pp. 41–59.
By 1792, the French republican position had become increasingly difficult. Compounding internal economic and social problems, French émigrés agitated abroad for support of a counter-revolution that would restore an absolute monarchy. Chief among them were Louis Joseph, Prince of Condé (cousin of Louis XVI), Condé's son, Louis Henri, Duke of Bourbon, and Condé's grandson, Louis Antoine, Duke of Enghien. From their base in Koblenz, immediately over the French border, they sought direct support for military intervention from the royal houses of Europe, and themselves raised a small army. The ascension of young and uncompromising Francis as Holy Roman Emperor-elect on the death of his father in July 1792 also contributed to their unease.
On 20 April 1792, the French National Convention declared war on Austria. In this War of the First Coalition (1792–98), France ranged itself against most of the European states sharing land or water borders with her, plus Portugal and the Ottoman Empire. Although the Coalition forces achieved several victories at Verdun, Kaiserslautern, Neerwinden, Mainz, Amberg and Würzburg, the efforts of Napoleon Bonaparte in northern Italy pushed Austrian forces across the Italian-Austrian border and resulted in the negotiation of the Peace of Leoben (17 April 1797) and the subsequent Treaty of Campo Formio (October 1797).
From October 1797 until the Army of the Danube crossed into Germany in March 1799, the signatories of the Treaty of Campo Formio had avoided armed conflict. Despite their agreement at Campo Formio, the two primary combatants, France and Austria, remained suspicious of each other's motives. Several diplomatic incidents undermined the agreement. The French demanded additional territory not mentioned in the Treaty. The Habsburgs were reluctance to hand over designated territories, much less additional ones. The Congress at Rastatt proved inept at orchestrating the transfer of territories to compensate the German princes for their losses. Ferdinand of Naples refused to pay tribute to France, followed by a general Neapolitan rebellion, the French suppression, and the subsequent establishment of the Parthenopean Republic. Republicans in the Swiss cantons, supported by the French army, overthrew the central government in Bern and established the Helvetic Republic.Blanning, pp. 230–232.
Other factors contributed to the rising tensions. On his way to Egypt, Napoleon had stopped on Malta and forcibly removed the Hospitallers from their possessions, angering Paul, Tsar of Russia, who was the honorary head of the Order. The French Directory, furthermore, was convinced that the Austrians were conniving to start another war. Indeed, the weaker the French Republic seemed, the more seriously the Austrians, the Neapolitans, the Russians and the English actually discussed this possibility.John Gallagher. Napoleon's enfant terrible: General Dominique Vandamme, Tulsa: University of Oklahoma Press, 2008, p. 70.
Purpose and formation
Military planners in Paris understood that the northern Rhine Valley, the south-western German territories, and Switzerland were strategically important for the defense of the Republic. The Swiss passes commanded access to northern Italy; consequently, the army that held those passes could move troops to and from northern and southern theaters quickly. The river was a formidable barrier to what the French perceived as Austrian aggression, and the state that controlled its crossings controlled the river itself. Finally, control of the Upper Danube would allow France to move its troops from Italy to the North Sea, or any point in between, offering immense strategic value.Gunther E. Rothenberg. Napoleon’s great adversaries: Archduke Charles and the Habsburg Army, 1792–1914, Stroud, (Gloucester): Spellmount, 2007, pp. 70–74.
Toward this end, in the early November 1798, Jourdan arrived in Hüningen, near the Swiss city of Basel, to take command of the Army of Observation, so-called because its function was to observe the security of the French border on the Rhine. Once there, Jourdan assessed the quality and disposition of the forces and identified needed supplies and manpower. He found the army woefully inadequate for its assignment. The Army, and its flanking armies, the Army of Helvetia (Switzerland) and the Army of Mayence, were equally short of manpower, supplies, ammunition, and training. Jourdan documented assiduously these shortages, pointing out in lengthy correspondence to the Directory the consequences of an under-manned and under-supplied army; his petitions seemed to have little effect on the Directory, which sent neither significant additional manpower nor supplies.Jean-Baptiste Jourdan. A Memoir of the operations of the army of the Danube under the command of General Jourdan, taken from the manuscripts of that officer. London: Debrett, 1799, pp. 60–90.
Jourdan's orders were to take the army into Germany and secure strategic positions, particularly on the roads through Stockach and Schaffhausen, at the westernmost border of Lake Constance. Similarly, as commander of the Army of Helvetia, André Masséna would acquire strategic positions in Switzerland, in particular the St. Gotthard Pass, the passes above Feldkirch, particularly Maienfeld (St. Luciensteig), and hold the central plateau in and around Zürich and Winterthur. These positions would prevent the Allies of the Second Coalition from moving troops back and forth between the northern Italian and German theaters, and insure French access to these strategic passes. Ultimately, this positioning would allow the French to control all western roads leading to and from Vienna. Finally, to complete Vienna's isolation, the army of Mayence would sweep through the north, blocking further access to and from Vienna from any of the northern Provinces, or from Britain.Jourdan, pp. 50–60
Crossing the Rhine On March 1, 1799, the Army of Observation, in an order of battle of approximately 30,000 men in four divisions, crossed the Rhine at Kehl and Basel as units crossed, they took the name Army of the Danube.Jourdan, p. 140.
Advance Guard, with approximately 9,000 men under General François Joseph Lefebvre, and temporarily commanded by Dominique Vandamme. This also included the detached left flank of 3,000 Vandamme eventually used to take Stuttgart.Jourdan, pp. 96–97. I. Division, with approximately 8,000 men under General Pierre Marie Barthélemy Ferino. II. Division, with approximately 7,000 men under General Joseph Souham.Jourdan, p. 97. III. Division, approximately 7,000 men under Laurent Saint-Cyr constituted the left flank. Reserve, with approximately 3,000 men under Jean-Joseph Ange d'Hautpoul.
The army advanced in four columns. First Division, the right wing, assembled at Hüningen, crossed at Basel and advanced eastward along the north shore of the Rhine toward Lake Constance.Masséna sent a Demi-brigade to secure the Swiss town of Schaffhausen, on the north shore of the Rhine, which guaranteed communications between the two forces. Jourdan, pp. 96–97. The Advanced Guard crossed at Kehl, and Vandamme led it north-east through the mountains via Freudenstadt. This column eventually became the left flank. It was followed across the Rhine, also at Kehl, by the II. Division. The Third Division and the Reserve also crossed at Kehl, and then divided into two columns, III. Division traveling through the Black Forest via Oberkirch, and the Reserve, with most of the artillery and horse, further south via the valley at Freiburg im Breisgau, where they would find more forage, and then over the mountains past the Titisee to Löffingen and Hüfingen.
Although Jourdan could have established a position on the immediate eastern slope of the mountains—and indeed he might have been better advised to do so—he pushed eastward across the Danube plain, taking a temporary position between Rottweil and Tuttlingen. Eventually he directed the army to establish a line centered in Pfullendorf. He planned to engage the Habsburg army under the Habsburg commander-in-chief Archduke Charles on the Ostrach plateau.Blanning, p. 232; Rothenburg, p. 74