The Ulm campaign lasted for nearly a month and saw the French army under Napoleon deliver blow after blow to the confused Austrians. It culminated on 20 October with the loss of an entire Austrian army.
Austrian plans and preparations On 9 September 1805, an Austrian army directed by Mack but under the nominal command of
General der Kavallerie Archduke Ferdinand Karl Joseph of Austria-Este crossed the frontier into the
Electorate of Bavaria without a declaration of war. It was hoped that the Austrian army, would compel the Bavarian army to join the Third Coalition against France. However, the Bavarian elector had signed a secret treaty with France and moved his army north to
Würzburg in order to rendezvous with French forces. By 18 September, Mack's army was arrayed near
Ulm where it watched the
Black Forest to the west. Mack expected that it would take the French two months to react, but Emperor
Napoleon's Grand Army was already on the march and by 24 September it was on the
Rhine River. Mack's initial deployment of the Austrian army was as follows. FML
Johann Kollowrat with 24 battalions was posted at Ulm. FML
Michael von Kienmayer guarded Mack's right rear on the
Danube River at
Ingolstadt with 6 battalions and 16 squadrons. The other forces lay farther south. They were FML
Karl Philipp, Prince of Schwarzenberg with 21 battalions and 46 squadrons near
Ravensburg, FML
Franz Xaver von Auffenberg with 14 battalions and 8 squadrons at
Kempten, FML
Franz Jellacic with 19 battalions and 8 squadrons at
Lindau on
Lake Constance, and FML
Franz von Werneck with 15 battalions and 8 squadrons at
Landsberg am Lech. Altogether, the Austrian army in Bavaria numbered 66,000 infantry and 9,000 cavalry. Mack expected that the French army would attack from the west. Mack thought that Austrian security relied on sealing off the gaps through the mountainous Black Forest area in southern Germany that had witnessed much fighting during the campaigns of the French Revolutionary Wars. Mack believed that there would be no action in central Germany. Mack decided to make the city of Ulm the centerpiece of his defensive strategy, which called for a containment of the French until the Russians under Kutuzov could arrive and alter the odds against Napoleon. Ulm was protected by the heavily fortified Michelsberg heights, giving Mack the impression that the city was virtually impregnable from outside attack. Fatally, the Aulic Council decided to make Northern Italy the main theater of operations for the
Habsburgs.
Archduke Charles was assigned 95,000 troops and directed to cross the
Adige River with
Mantua,
Peschiera, and
Milan as the initial objectives. The Austrians based an army of 72,000 men on Ulm. Nominally commanded by
Archduke Ferdinand, the army's real authority was Mack. Austrian strategy required that
Archduke John with 23,000 troops secure the
Tyrol and provide the link between his brother Charles's army and his cousin Ferdinand's army. The Austrians also detached individual corps to serve with the Swedish in
Pomerania and the British in
Naples, though these were designed to confuse the French and divert their resources.
French plans and preparations from early to mid-September. 210,000 troops of the prepared to cross into Germany and encircle the Austrians. In both the campaigns of 1796 and 1800, Napoleon had envisaged the Danube theater as the central focus of French efforts, but in both instances the Italian theater became the most important. The Aulic Council thought Napoleon would strike in Italy again. Napoleon had other intentions: 210,000 French troops would be launched eastwards from the camps of Boulogne and would envelop General Mack's exposed Austrian army if it kept marching towards the
Black Forest. Meanwhile,
Marshal Murat would conduct cavalry screens across the Black Forest to fool the Austrians into thinking that the French were advancing on a direct west-east axis. The main attack in Germany would be supported by French assaults in other theaters: Marshal
Masséna would confront Charles in Italy with 50,000 men of the ''
Armée d'Italie'',
St. Cyr would march to Naples with 20,000 men, and Marshal
Brune would patrol Boulogne with 30,000 troops against a possible British invasion. Murat and
Henri Gratien, Comte Bertrand conducted reconnaissance between the area bordering the Tyrol and the
Main as
Anne Jean Marie René Savary, chief of the planning staff, drew up detailed road surveys of the areas between the Rhine and the Danube. The left wing of the would move from
Hanover in northern Germany and
Utrecht in the Netherland to fall on
Württemberg; the right and center, troops from the Channel coast, would concentrate along the
Middle Rhine around cities like
Mannheim and
Strasbourg. While Murat was making demonstrations across the Black Forest, other French forces would then invade the German heartland and swing towards the southeast by capturing
Augsburg, a move that was supposed to isolate Mack and interrupt the Austrian lines of communication.
The French invasion On 22 September Mack decided to hold the
Iller line anchored on Ulm. In the last three days of September, the French began the furious marches that would place them at the Austrian rear. Mack believed that the French would not violate Prussian territory, but when he heard that Marshal
Jean Baptiste Bernadotte's I Corps had marched through Prussian
Ansbach, he made the critical decision to stay and defend Ulm rather than retreat to the south, which would have offered a reasonable opportunity at saving the bulk of his forces. Napoleon had little accurate information about Mack's intentions or maneuvers; he knew that Kienmayer's Corps was sent to
Ingolstadt east of the French positions, but his agents greatly exaggerated its size. On 5 October Napoleon ordered Marshal
Michel Ney to join Marshals
Jean Lannes,
Nicolas Jean de Dieu Soult, and Murat in concentrating and crossing the Danube at
Donauwörth. The French encirclement, however, was not deep enough to prevent Kienmayer's escape: the French corps did not all arrive at the same place – they instead deployed on a long west-east axis – and the early arrival of Soult and Davout at Donauwörth induced Kienmayer to exercise caution and evasion. Napoleon gradually became more convinced that the Austrians were massed at Ulm and ordered sizeable portions of the French army to concentrate around Donauwörth; on 6 October three French infantry and cavalry corps headed to Donauwörth to seal off Mack's escape route. Realizing the danger of his position, Mack decided to go on the offensive. On 8 October he commanded the army to concentrate around
Günzburg and hoped to strike at Napoleon's lines of communication. Mack instructed Kienmayer to draw Napoleon further east towards
Munich and Augsburg. Napoleon did not seriously consider the possibility that Mack would cross the Danube and move away from his central base, but he did realize that seizing the bridges at Günzburg would yield a large strategic advantage. To accomplish this objective, Napoleon sent Ney's Corps to Günzburg, completely unaware that the bulk of the Austrian army was heading to the same destination. On 8 October, however, the campaign witnessed its first serious battle at
Wertingen between Auffenberg's troops and those of Murat and Lannes.
Battle of Wertingen For reasons not entirely clear, on 7 October Mack ordered Auffenberg to take his division of 5,000 infantry and 400 cavalry from Günzburg to Wertingen in preparation for the main Austrian advance out of Ulm. Uncertain of what to do and having little hope for reinforcements, Auffenberg was in a dangerous position. The first French forces to arrive were Murat's cavalry divisions –
General of Division (GD)
Louis Klein's 1st
Dragoon Division, GD
Marc Antoine de Beaumont's 3rd Dragoon Division, and GD
Etienne de Nansouty's 1st
Cuirassier Division. They began to assault the Austrian positions and were soon joined by GD
Nicolas Oudinot's grenadiers, who were hoping to outflank the Austrians from the northeast. Auffenberg attempted a retreat to the southwest, but he was not quick enough: the Austrians lost nearly their entire force, 1,000 to 2,000 of which were taken prisoner. The
Battle of Wertingen had been an easy French victory. too far away to offer significant aid, the Austrians found themselves in a precarious position. The action at Wertingen convinced Mack to operate on the left (north) bank of the Danube instead of making a direct eastwards retreat on the right bank. This would require the Austrian army to cross to the north at Günzburg. On 8 October Ney was operating under Marshal
Louis Alexandre Berthier's directions that called for a direct attack on Ulm the following day. Ney sent in GD
Jean-Pierre Firmin Malher's 3rd Division to capture the Günzburg bridges over the Danube. In the
Battle of Günzburg, a column of this division ran into some Tyrolean jaegers and captured 200 of them, including their commander
Konstantin Ghilian Karl d'Aspré, along with two cannons. The Austrians noticed these developments and reinforced their positions around Günzburg with three infantry battalions and 20 cannons. Malher's division conducted several heroic attacks against the Austrian positions, but all failed. Mack then sent in
Ignaz Gyulai with seven infantry battalions and fourteen cavalry squadrons to repair the destroyed bridges, but this force was charged and swept away by the delayed French 59th Infantry Regiment. Fierce fighting ensued and the French finally managed to establish a foothold on the right (south) bank of the Danube. While the Battle of Günzburg was being fought, Ney sent GD
Louis Henri Loison's 2nd Division to capture the Danube bridges at
Elchingen, which were lightly defended by the Austrians. Having lost most of the Danube bridges, Mack marched his army back to Ulm. By 10 October Ney's corps had made significant progress: Malher's 3rd division had crossed to the right (south) bank, Loison's 2nd division held Elchingen, and
Pierre Dupont de l'Étang's 1st Division was heading towards Ulm.
Haslach-Jungingen and Elchingen The demoralized Austrian army arrived at Ulm in the early hours of 10 October. Mack was deliberating his course of action and the Austrian army remained inactive at Ulm until the 11th. Meanwhile, Napoleon was operating under flawed assumptions: he believed the Austrians were moving to the east or southeast and that Ulm was lightly guarded. Ney sensed this misapprehension and wrote to Berthier that Ulm was, in fact, more heavily defended than the French originally thought. During this time, the Russian threat to the east began to preoccupy Napoleon so much that Murat was given command of the right wing of the army, consisting of Ney's and Lannes's corps. The French were separated in two massive wings at this point: the forces of Ney, Lannes, and Murat to the west were containing Mack while those of Soult, Davout, Bernadotte, and GD
Auguste Marmont to the east were charged with guarding against any possible Russian and Austrian incursions. On 11 October Ney made a renewed push on Ulm; the 2nd and 3rd divisions were to march to the city along the right bank of the Danube while Dupont's division, supported by one dragoon division, was to march directly for Ulm and seize the entire city. The orders were hopeless because Ney still did not know that the entire Austrian army was stationed at Ulm. The 32nd Infantry Regiment in Dupont's division marched from
Haslach towards Ulm and ran into four Austrian regiments holding Boefingen. The 32nd carried out several ferocious attacks, but the Austrians held firm and repulsed every one. The Austrians flooded the battle with more cavalry and infantry regiments to
Ulm-Jungingen hoping to score a knockout blow against Ney's corps by enveloping Dupont's force. Dupont sensed what was happening and preempted the Austrians by launching a surprise attack on Jungingen, during which he took as prisoner at least 4,000 of the Austrians. Renewed Austrian attacks drove these forces back to Haslach, which the French managed to hold. Dupont was eventually forced to fall back on Albeck, where he joined
Louis Baraguey d'Hilliers's foot dragoons division. The effects of the
Battle of Haslach-Jungingen on Napoleon's plans are not fully clear, but the Emperor may have finally ascertained that the majority of the Austrian army was concentrated at Ulm. Accordingly, Napoleon sent the corps of Soult and Marmont towards the Iller, meaning he now had four infantry and one cavalry corps to deal with Mack; Davout, Bernadotte, and the Bavarians were still guarding the region around Munich. Napoleon did not intend to fight a battle across rivers and ordered his marshals to capture the important bridges around Ulm. He also began shifting his forces to the north of Ulm because he expected a battle in that region rather than an encirclement of the city itself. These dispositions and actions would lead to a confrontation at Elchingen on the 14th as Ney's forces advanced on Albeck. At this point in the campaign, the Austrian command staff was in full confusion. Ferdinand began to openly oppose Mack's command style and decisions, charging that the latter spent his days writing contradictory orders that left the Austrian army marching back and forth. On 13 October Mack sent two columns out of Ulm in preparation for a breakout to the north: one under
Johann Sigismund Riesch headed towards Elchingen to secure the bridge there and the other under
Franz von Werneck went north with most of the heavy artillery. Ney hurried his corps forward to reestablish contact with Dupont, who was still north of the Danube. Ney led Loison's division to the south of Elchingen on the right bank of the Danube to begin the attack. Malher's division crossed the river farther east and moved west toward Riesch's position. The field was a partially wooded flood plain, rising steeply to the hill town of Elchingen, which had a wide field of view. The French cleared the Austrian pickets from a bridge, then a regiment boldly attacked and captured the abbey at the top of the hill at bayonet point. During the
Battle of Elchingen, the Austrian cavalry was also defeated and Reisch's infantry fled toward Ulm. Ney was given the title
Duke of Elchingen for his impressive victory.
Battle of Ulm proved instrumental during the Ulm campaign. On 13 October Soult's IV Corps fell on
Memmingen from the east. After a minor clash that resulted in 16 French casualties, General-Major Karl Spangen von Uyternesse surrendered 4,600 soldiers, eight guns, and nine colors. The Austrians were low on ammunition, cut off from Ulm, and completely demoralized by the confusion reigning at army headquarters. More actions took place on the 14th. Murat's forces joined Dupont at Albeck just in time to drive off an Austrian attack from Werneck; together Murat and Dupont beat the Austrians to the north in the direction of
Heidenheim. By night on the 14th, two French corps were stationed in the vicinity of the Austrian encampments at Michelsberg, right outside of Ulm. Mack was now in a dangerous situation: there was no longer any hope of escaping along the north bank, Marmont and the
Imperial Guard were hovering at the outskirts of Ulm to the south of the river, and Soult was moving north from Memmingen to prevent the Austrians escaping south to the Tyrol. Troubles continued with the Austrian command as Ferdinand overrode the objections of Mack and ordered the evacuation of all cavalry from Ulm, a total of 6,000 troopers. Murat's pursuit was so effective, however, that only eleven squadrons joined Werneck at Heidenheim. Murat continued his harassment of Werneck and forced him to surrender with 8,000 men at Trochtelfingen on 19 October; Murat also took an entire Austrian field park of 500 vehicles, then swept on towards
Neustadt an der Donau and captured 12,000 Austrians. Events at Ulm were now reaching a conclusion. On 15 October Ney's troops successfully charged the Michelsberg encampments and on the 16th the French began to bombard Ulm itself. Austrian morale was at a low point and Mack began to realize that there was little hope of rescue. On 17 October Napoleon's emissary,
Ségur, signed a convention with Mack in which the Austrians agreed to surrender on 25 October if no aid came by that date. Gradually, however, Mack heard of the capitulations at Heidenheim and
Neresheim and agreed to surrender five days before schedule on 20 October. Fifteen hundred troops from the Austrian garrison managed to escape, but the vast majority of the Austrian force marched out on 21 October and laid down their arms without incident, all with the drawn up in a vast semicircle observing the capitulation (see infobox picture). The officers were permitted to leave, pending their signatures on a parole in which they agreed not to take up arms against France until they were exchanged. More than ten general officers were included in this agreement, including Mack,
Johann von Klenau,
Maximilian Anton Karl, Count Baillet de Latour,
Prince Liechtenstein, and
Ignaz Gyulai. ==Aftermath==