In the Rhine campaign of 1796 (June 1796 to February 1797), two First Coalition armies under the overall command of Archduke Charles outmaneuvered and defeated two French Republican armies. This was the last campaign of the War of the First Coalition, part of the French Revolutionary Wars.
The French military strategy against Austria called for a three-pronged invasion to surround Vienna, ideally capturing the city and forcing the Holy Roman emperor, Francis II, to surrender and accept French Revolutionary territorial integrity. The French assembled the Army of Sambre and Meuse commanded by Jean-Baptiste Jourdan against the Austrian Army of the Lower Rhine in the north. The Army of the Rhine and Moselle, led by Jean Victor Marie Moreau, opposed the Austrian Army of the Upper Rhine in the south. A third army, the Army of Italy, commanded by Napoleon Bonaparte, approached Vienna through northern Italy.
The early success of the Army of Italy initially forced the Coalition commander, Archduke Charles, to transfer 25,000 men commanded by Dagobert Sigmund von Wurmser to northern Italy. This weakened the Coalition force along the 340-kilometre (211 mi) front stretching along the Rhine from Basel to the North Sea. Later, a feint by Jourdan's Army of Sambre and Meuse convinced Charles to shift troops to the north, allowing Moreau to cross the Rhine at the Battle of Kehl on 24 June and defeated the Archduke's Imperial contingents. Both French armies penetrated deep into eastern and southern Germany by late July, forcing the southern states of the Holy Roman Empire into punitive armistices. By August, the French armies had extended their fronts too thinly and rivalry among the French generals complicated cooperation between the two armies. Because the two French armies operated independently, Charles was able to leave Maximilian Anton Karl, Count Baillet de Latour with a weaker army in front of Moreau on the southernmost flank and move many reinforcements to the army of Wilhelm von Wartensleben in the north.
At the Battle of Amberg on 24 August and the Battle of Würzburg on 3 September, Charles defeated Jourdan's northern army and compelled the French to retreat, eventually to the west bank of the Rhine. With Jourdan neutralized and retreating into France, Charles left Franz von Werneck to watch the Army of Sambre and Meuse, making sure it did not try to recover a foothold on the east bank of the Rhine. After securing the Rhine crossings at Bruchsal and Kehl, Charles forced Moreau to retreat south. During the winter the Austrians reduced the French bridgeheads in the sieges of Kehl and the Hüningen, and forced Moreau's army back to France. Despite Charles' success in the Rhineland, Austria was defeated in the Italian campaign of 1796–1797, which resulted in the Peace of Campo Formio.
Background
The rulers of Europe initially viewed the French Revolution as an internal dispute between the French king Louis XVI and his subjects. As revolutionary rhetoric grew more strident, the monarchs of Europe declared their interests as one with those of Louis and his family. The Declaration of Pillnitz (27 August 1791) threatened ambiguous, but quite serious, consequences if anything should happen to the French royal family. French émigrés, who had the support of the Habsburgs, the Prussians, and the British, continued to agitate for a counter-revolution.
Finally, on 20 April 1792, the French National Convention declared war on the Habsburg monarchy, pushing all of the Holy Roman Empire into war. Consequently, 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 Great Britain and the Kingdom of Portugal.
From 1793 to 1795, French successes varied. By 1794, the armies of the French Republic were in a state of disruption. The most radical of the revolutionaries purged the military of all men conceivably loyal to the Ancien Régime. The levée en masse created a new army with thousands of illiterate, untrained men placed under the command of officers whose principal qualifications may have been their loyalty to the Revolution instead of their military acumen. Traditional military organization was disrupted by the formation of the new demi-brigade, units created by the amalgamation of old military units with new revolutionary formations: each demi-brigade included one unit of the old royalist army and two from the new mass conscription. The losses of this revolutionized army in the Rhine campaign of 1795 disappointed the French public and the French government.
Furthermore, by 1795, the army had already made itself odious throughout France, by both rumor and action, through its rapacious dependence upon the countryside for material support and its general lawlessness and undisciplined behavior. After April 1796, the military was paid in metallic rather than worthless paper currency, but pay was still well in arrears. The French Directory believed that war should pay for itself and did not budget to pay, feed, and equip its troops. Thus, a campaign that would take the army out of France became increasingly urgent for both budgetary and internal security reasons.
Political terrain
The predominantly German-speaking states on the east bank of the Rhine were part of the vast complex of territories in central Europe called the Holy Roman Empire, of which the Archduchy of Austria was a principal polity and its archduke typically the Holy Roman emperor. The French government considered the Holy Roman Empire as its principal continental enemy. The territories in the Empire of late 1796 included more than 1,000 entities, including Breisgau (Habsburg), Offenburg and Rottweil (free cities), the territories belonging to the princely families of Fürstenberg and Hohenzollern, the Duchy of Baden, the Duchy of Württemberg, and several dozen ecclesiastic polities. Many of these territories were not contiguous: a village could belong predominantly to one polity, but have a farmstead, a house, or even one or two strips of land that belonged to another polity. The size and influence of the polities varied, from the Kleinstaaterei, the little states that covered no more than a few square miles, or included several non-contiguous pieces, to such sizable, well-defined territories as Bavaria and Prussia.
The governance of these states also varied: they included the autonomous free Imperial cities (also of different sizes and influence), ecclesiastical territories, and dynastic states such as Württemberg. Through the organization of Imperial Circles, also called Reichskreise, groups of states consolidated resources and promoted regional and organizational interests, including economic cooperation and military protection. Without the participation of such principal states of the Empire as the Archduchy of Austria, Prussia, the Electorate of Saxony, and Bavaria, for example, these small states were vulnerable to invasion and conquest because they were unable to defend themselves on their own.
Geography
The Rhine formed the boundary between the German states of the Holy Roman Empire and its neighbors. Any attack by either party required control of the crossings. The river began in the Swiss canton of Graubünden (also called the Grisons) near Lake Toma and flowed along the Alpine region bordered by Liechtenstein, northward into Lake Constance, where it traversed the lake. From Lake Constance, the river left the lake at Stein am Rhein and flowed westerly along the border between the German states and the Swiss cantons. The c. 150-kilometre (93 mi) stretch between Stein am Rhein and Basel, called the High Rhine, cut through steep hillsides only near the Rhine Falls and flowed over a gravel bed; in such places as the former rapids at Laufenburg, or after the confluence with the even larger Aare below Koblenz, Switzerland, it moved in torrents.
At Basel, where the terrain flattened, the Rhine made a wide, northerly turn at the Rhine knee, and entered what the locals call the Rhine Ditch (Rheingraben). This formed part of a rift valley some 31 kilometres (19 mi) wide bordered by the mountainous Black Forest on the east (German side) and the Vosges mountains on the west (French side). At the far edges of the eastern flood plain, tributaries cut deep defiles into the western slope of the mountains; this became especially important in the rainy autumn of 1796. Further to the north, the river became deeper and faster, until it widened into a delta, where it emptied into the North Sea. In the 1790s, this part of the river was wild and unpredictable and armies crossed at their peril. River channels wound through marsh and meadow, and created islands of trees and vegetation that were periodically submerged by floods. Flash floods originating in the mountains could submerge farms and fields. Any army wishing to traverse the river had to cross at specific points: in 1790, systems of viaducts and causeways made access across the river reliable, but only at Kehl, by Strasburg, at Hüningen, by Basel, and in the north by Mannheim. Sometimes, crossing could be executed at Neuf-Brisach, between Kehl and Hüningen, but the small bridgehead made this unreliable. Only to the north of Kaiserslauten did the river acquire a defined bank where fortified bridges offered reliable crossing points.
War plans
At the end of the Rhine Campaign of 1795 the two sides had called a truce, but both sides continued to plan for war. In a decree on 6 January 1796, Lazare Carnot, one of the five French Directors, gave Germany priority over Italy as a theater of war. The French First Republic's finances were in poor shape so its armies would be expected to invade new territories and then live off the conquered lands. Knowing that the French planned to invade Germany, on 20 May 1796 the Austrians announced that the truce would end on 31 May, and prepared for invasion.
Habsburg and Imperial organization
Initially, the Habsburg and Imperial troops numbered about 125,000, including three autonomous corps, of which 90,000 were commanded by the 25-year-old Archduke Charles, brother of the Holy Roman emperor, Francis II. Before the campaign in the Rhineland started, Dagobert Sigmund von Wurmser took 25,000 of these as reinforcements to Italy after news arrived of Bonaparte's early successes. In the new situation, the Aulic Council, the Emperor's war advisors, gave Charles command over Austrian forces that had been transferred from the border provinces, and over the Imperial contingents (Kreistruppen) of the Holy Roman Empire. The Austrian strategy was to capture Trier and to use this position on the west bank to strike at each of the French armies in turn; failing that, the Archduke was to hold his ground.
The 20,000-man right (north) wing under Duke Ferdinand Frederick Augustus of Württemberg stood on the east bank of the Rhine behind the river Sieg, observing the French bridgehead at Düsseldorf. A portion patrolled the west bank and behind the river Nahe. The Mainz Fortress and Ehrenbreitstein Fortress garrisons totaled about 10,000 more, including 2,600 at Ehrenbreitstein. Charles concentrated the bulk of his force, commanded by one of his more experienced generals, Count Baillet Latour, between Karlsruhe and Darmstadt, where the confluence of the Rhine and the Main made an attack most likely; the rivers offered a gateway into eastern German states and ultimately to Vienna, with good bridges crossing a relatively well-defined river bank. A force occupied Kaiserslautern on the west bank. Wilhelm von Wartensleben's autonomous corps covered the line between Mainz and Giessen.
The far left wing, under Anton Sztáray, Michael von Fröhlich and Louis Joseph, Prince of Condé, guarded the Rhine border from Mannheim to Switzerland. This part of the army included the conscripts drafted from the Imperial Circles. Charles did not like to use the militias in any vital location and once it seemed clear to him that the French intended to cross at the middle Rhine, the Archduke felt no qualms placing his militia men at Kehl. In Spring 1796, when resumption of war appeared imminent, the 88 members of the Swabian Circle, which included most of the states (ecclesiastical, secular, and dynastic) in Upper Swabia, had raised a small force of about 7,000 men. These were field hands, the occasional journeyman, and day laborers drafted for service, but untrained in military matters. The remainder of the force included experienced troops from the Habsburg frontier troops stationed just north of Rastatt, and a cadre of French royalists and a couple of hundred mercenaries at Freiburg im Breisgau.
Compared to French, Charles had half the number of troops covering a 340-kilometer (340,000 m) front that stretched from Switzerland to the North Sea in what Gunther Rothenberg called the "thin white line". Imperial troops could not cover the territory from Basel to Frankfurt with sufficient depth to resist the pressure of their opponents.
French organization
Lazare Carnot's grand plan called for the two French armies along the Rhine to press against the Austrian flanks. These armies were to be commanded by two of their most experienced generals, Jean-Baptiste Jourdan and Jean Victor Moreau, who led (respectively) the Army of Sambre and Meuse and the Army of the Rhine and Moselle at the outset of the 1796 campaign.
Moreau's army was positioned east of the Rhine at Hüningen and to the north, its center along the river Queich near Landau and its left wing extended west toward Saarbrücken. The Army of Rhine and Moselle numbered 71,581 foot soldiers and 6,515 cavalry, excluding gunners and sappers. The 80,000-man Army of Sambre and Meuse already held the west bank of the Rhine as far south as the Nahe and then southwest to Sankt Wendel. On the army's left (northern) flank, Jean Baptiste Kléber had 22,000 troops in a bridgehead on the eastern bank of the Rhine in an entrenched camp at Düsseldorf. Kléber was to push south from Düsseldorf, while Jourdan's main force would besiege Mainz and then cross the Rhine into Franconia. It was hoped that this advance would induce the Austrians to withdraw all of their forces from the Rhine's west bank to face the French onslaught. While Jourdan's actions near Düsseldorf drew Austrian attention northward, Jean Victor Marie Moreau was to lead the Army of Rhine and Moselle across the Rhine at Neuf-Breisach, Kehl and Hüningen, invade the Duchy of Baden, besiege or take Mannheim, and subdue Swabia and the Duchy of Bavaria. Ultimately, Moreau was to converge on Vienna; Jourdan, who by mid-summer theoretically should have taken most of Franconia, would veer south to provide a rearguard for Moreau's advance on the Habsburg capital.