The Battle of Ostrach, also called the Battle by Ostrach, occurred on 20–21 March 1799. It was the first non-Italy-based battle of the War of the Second Coalition. The battle resulted in the victory of the Austrian forces, under the command of Archduke Charles, over the French forces, commanded by Jean-Baptiste Jourdan.
The battle occurred during Holy Week, 1799, amid rain and dense fog. Initially, the French were able to take, and hold, Ostrach and the nearby hamlet of Hoßkirch plus several strategic points on the Ostrach marsh. As the engagement began, Habsburg numerical superiority overwhelmed French defenses. By evening, the French left wing was flanked and Jourdan's men retreated from Ostrach to the Pfullendorf heights. On the next morning, as Jourdan considered a counter-attack, the weather broke, and he could look down on the Austrian battle array. The numbers and dispositions of the Austrians convinced him that any attack would be useless, and that he could not hope to maintain his position in the heights. As he withdrew, a portion of his right flank was cut off from the main force.
Although casualties appeared even on both sides, the Austrians had a significantly larger fighting force, both on the field at Ostrach, and stretched along a line between Lake Constance and Ulm. French casualties amounted to eight percent of the force and Austrian, approximately four percent. The French withdrew to Engen and Stockach, where a few days later the armies engaged again, this time with greater losses on both sides, and an Austrian victory.
Background
Initially, the rulers of Europe, such 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, however, the other monarchies started to view events with alarm. In 1790, Leopold succeeded his brother Joseph as emperor and by 1791, he considered the situation surrounding his sister, Marie Antoinette, and her children, with greater and greater alarm. In August 1791, in consultation with French émigré nobles and Frederick William II of Prussia, he 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 ambiguous, but quite serious, consequences if anything should happen to the royal family.
The French Republican position became increasingly difficult. Compounding problems in international relations, French émigrés continued to agitate for support of a counter-revolution abroad. Chief among them were the Prince Condé, his son, the Duke de Bourbon, and his grandson, the Duke d'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 raised an army.
On 20 April 1792, the French National Convention declared war on Austria. In this War of the First Coalition (1792–1798), 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 back and resulted in the negotiation of the Peace of Leoben (17 April 1797) and the subsequent Treaty of Campo Formio (October 1797).
The treaty called for meetings between the involved parties to work out the exact territorial and remunerative details, to be convened at Rastatt. The French demand for more territory than originally agreed upon stalled negotiations. Despite their agreement at Campo Formio and the ongoing meetings at Rastatt, the two primary combatants of the First Coalition, France and Austria, were highly suspicious of the other's motives. Several diplomatic incidents undermined the agreement. The Austrians were reluctant to cede the designated territories and the Rastatt delegates could not, or would not, orchestrate the transfer of agreed upon territories to compensate the German princes for their losses. Ferdinand of Naples refused to pay tribute to France, followed by the Neapolitan rebellion, invasion by France, and the subsequent establishment of the Parthenopean Republic. Republican uprising in the Swiss cantons, encouraged by the French Republic with military support, led to the establishment of the Helvetic Republic.
Other factors contributed to the rising tensions as well. On his way to Egypt in 1798, Napoleon had stopped on the Island of Malta and forcibly removed the Hospitallers from their possessions. This angered 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.
Prelude
Archduke Charles of Austria had taken command of the army in late January. Although he was unhappy with the strategy set forward by his brother, the Holy Roman Emperor Francis II, he had acquiesced to the less ambitious plan to which Francis and the Aulic Council had agreed: Austria would fight a defensive war and would maintain a continuous defensive line from the Danube to northern Italy. The archduke had stationed himself at Friedberg for the winter, 4.7 miles (8 km) east-south-east of Augsburg. The army was already settled into cantonments in the environs of Augsburg, extending south along the Lech river.
As winter broke in 1799, on 1 March, General Jean-Baptiste Jourdan and his army of 25,000, the so-called Army of the Danube, crossed the Rhine at Kehl. Instructed to block the Austrians from access to the Swiss alpine passes, the Army of the Danube would ostensibly isolate the armies of the Coalition in Germany from allies in northern Italy, and prevent them from assisting one another; furthermore, if the French held the interior passes in Switzerland, they could use the routes to move their own forces between the two theaters. The Army of the Danube, meeting little resistance, advanced through the Black Forest in three columns, through the Höllental (Hölle valley), via Oberkirch, and Freudenstadt, and a fourth column advanced along the north shore of the Rhine. Although Jourdan might have been better advised to establish a position on the eastern slope of the mountains, he did not. Instead, he pushed across the Danube plain and took up position between Rottweil and Tuttlingen, and eventually pushing toward the imperial city of Pfullendorf in Upper Swabia.
News of the French advance across the Rhine took three days to reach Charles at Augsburg. The Austrian Vorhut (advance guard), 17,000 men under the command of Field marshal Friedrich Joseph, Count of Nauendorf, crossed the Lech in three columns, the first at Babenhausen, marching in the direction of Biberach, the second, and strongest, at Memmingen, marching in the direction of Waldsee, and the third at Leutkirch, heading in the direction of Ravensburg. The main force of 53,000 men, under the command of the Archduke, crossed the Lech by Augsburg, Landsberg and Schongau, and six battalions of 6,600 men crossed the Danube at Ulm. An additional force of 13,000 troops under the command of Lieutenant Field Marshal Anton Sztáray marched toward Neumarkt in the direction of Rednitz. Eventually, 10,000 men under the command of General Friedrich Freiherr von Hotze marched north from Feldkirch in Switzerland, but they did not arrive in time to participate at either the battle at Ostrach, or for the subsequent battle at Stockach.
Locale
Ostrach was a small village, with a population of 300. The village belonged to the Cistercian Imperial Abbey of Salem, an influential and wealthy ecclesiastical territory on Lake Constance. The village was largely dedicated to farming, although a stretch of the imperial post road connected it and Pfullendorf. A wide, flat plain, marshy in places, stretched between the base of the Pfullendorf heights and the village; low lying hills ringed the valley, which was creased by a small stream from which the village takes its name. Ostrach itself lies almost at the northern end of this plain, but slightly south of the Danube itself. The two armies faced each other across this small and, at that time of that year, very soggy valley.
Dispositions
By 7 March, the first Austrian soldiers arrived in Ostrach. The French advance guard arrived by the 9th, under command of General François Joseph Lefebvre; in the forward line, the 25th Demi-brigade and Light Infantry positioned themselves between Ostrach and Hoßkirch; Lefebvre also had three battalions each of the 53rd and 67th Demi-Brigades of light infantry, twenty squadrons of hussars, chasseurs, and dragoons, and field artillery pieces. By 12 March, the village and the surrounding farms were filled with Lancers (Ulanen) and Hussars (Hussaren) and by the 17th, the Austrian advance guard had established forward posts at Buchau, Altshausen and Waldsee. The remainder of Charles' army, at this point nearly 110,000 strong, had established itself along a line from Ulm to Lake Constance.
By 18 March, Jourdan had formed his headquarters at Pfullendorf, on the heights above Ostrach. In front of him stood the largest part of his cavalry and half of his infantry. The center, including the 4th Regiment of Hussars, the 1st of Chasseurs à Cheval, and two squadrons of the 17th Dragoons, lay behind Ostrach, under command of General
Klein. Jourdan distributed them in three columns, the strongest on the post road by Saulgau, another on the road in the direction of Altshausen, and a third at the hamlet of Friedberg.
The flank of Lefebvre's division, with 7,000 men, commanded by Laurent Saint-Cyr extended to the Danube; by the time skirmishing began, Vandamme, was still in the environs of Stuttgart, with 3,000 men, looking in vain for Austrian forces that might be stationed there, and he played no part in the battle. The far right, under command of Ferino, angled south from Pfullendorf to Lake Constance, or the Bodensee. The cavalry reserve of 3,000 under General Jean-Joseph Ange d'Hautpoul included a battalion of the 53rd Demi-Brigade, and waited in close column in the environs of Pfullendorf.
Battle
Jourdan considered his position superior to the Austrian's, protected as he was by the marshy plain between his positions and the Austrian front, and he thought he had another three days to consolidate his positions. His forces occupied Hoßkirch, and a couple of other points he considered strategic: the causeway (post road) that passed Saulgau (today Bad Saulgau), the village of Altshausen 11 kilometers (7 mi) east, and the hamlet of Friedberg, 5 kilometers (3 mi) to the north-north-east of Ostrach. These positions created a perimeter around Ostrach. He was unaware that the Archduke had arrived by forced marches from Augsburg to the vicinity of Ostrach; Jourdan thought the main force of Charles' army was still at least three days' march away. By the middle of Holy Week in 1799, more than a third of Charles' army, 48,000 mixed troops, was positioned in a formation parallel to Jourdan's, and his 72,000 remaining troops were arrayed with the left wing at Kempten, the center near Memmingen, and the right flank extended to Ulm.
Skirmishing
As the armies assembled in their positions, the flanks and forward outposts encountered one another in several skirmishes; indeed, they had been skirmishing for seven days, until 19 March, when the outposts of both armies nearly overlapped. On the right wing, General Ferino's men encountered an Austrian column of volunteer infantry and some light cavalry from one of the border Hussar regiments, and took 70 and 80 prisoners, respectively, including several officers. All of this happened without the Austrians knowing that there was an official declaration of war. On 20 March, a French emissary arrived at camp of Prince Schwarzenberg, a major general commanding a brigade of the advanced guard. The emissary asked if he possessed a declaration of war from Vienna, and upon being informed that Schwarzenberg had received no such declaration, informed him that the armistice established at Campo Formio was ended, and there existed between France and Austria a state of war. General Jourdan reportedly began a general attack when the emissary left, although other sources do not bear out the scale of the attack.
Initially, the strength of the French advance guard pushed the most forward of the Austrian right to Saulgau and Ratzenreute, 6.2 kilometers (4 mi) east of Ostrach, backing the Austrian main army against the Schussen river. Jean Victor Tharreau's mixed brigade of infantry, light infantry and cavalry encountered the Austrians at Barendorf, and forced them to give up the ground; immediately, Charles sent reinforcements, and the Austrians regained what they had lost.