Battle of Elchingen - Background

Background

On 8 September, the army of Feldmarschall-Leutnant Karl Mack and Feldmarschall-Leutnant Archduke Ferdinand of Austria-Este crossed the Inn River and invaded the Electorate of Bavaria. Mack planned to establish 88 battalions and 148 squadrons on the Lech River near Augsburg by the end of October. Though called upon to join Austria against France, Elector Maximilian IV Joseph of Bavaria instead withdrew his army north to the Main River in accordance with his secret alliance with France.

By 12 September when the Austrians occupied Munich, Mack changed his mind and discarded his earlier plan. He decided to concentrate his army farther west on the Iller River so he could counterattack any French invasion coming through the Black Forest. As part of his new strategy, Feldmarschall-Leutnant Franjo Jelačić (also Franz Jellacic) was ordered to move from Feldmarschall-Leutnant Archduke John's Army of the Tyrol to Lake Constance. Mack expected to have 50,000 to 55,000 troops in position near Ulm by the end of September. Jellačić would hold the left flank with 11,000 soldiers while Feldmarschall-Leutnant Michael von Kienmayer 12,000-man corps watched the Bavarians from Ingolstadt. However, the change of plans threw the Austrian army's supply system into disarray. As the weather turned bad, sickness and desertion began to diminish the army's numbers. The nominal army commander, Archduke Ferdinand and Mack's chief of staff General-Major Anton Mayer von Heldensfeld both insisted that the army halt at the Lech as originally planned. By the end of September, relations between Mack and Ferdinand became so poor that all communication between the two was done in writing.

Ferdinand and Mayer appealed to Emperor Francis II. The emperor sought the advice of Feldmarschall Archduke Charles, who commanded the Army of Italy, and was warned that Mack was making a strategic blunder. Even so, the emperor backed Mack to the hilt and relieved Mayer of his post. Mack's army began to assemble on the Iller. On 24 and 25 September, Napoleon launched the Grande Armée across the Rhine River to open the Ulm Campaign. While Marshal Joachim Murat's Cavalry Corps and Marshal Jean Lannes's V Corps advanced directly east toward Ulm, the bulk of Napoleon's army passed to the north of the Austrian army. Marshal Jean-Baptiste Bernadotte's I Corps, General of Division Auguste Marmont's II Corps, Marshal Louis Davout's III Corps, Marshal Nicolas Soult's IV Corps, and Marshal Ney's VI Corps wheeled east, then southeast, then south. On 5 October, Kienmayer reported that the French were in Ansbach, to the north of the Danube. Two days later, the French crossed the Danube on a broad front, moving south.

At this time Mack's army was divided into four corps. Jellačić had 15,000 troops in 16 infantry battalions, six jäger companies, and six cavalry squadrons to the south of Ulm. Feldmarschall-Leutnant Karl Philipp, Prince of Schwarzenberg commanded 28 battalions and 30 squadrons at Ulm. Feldmarschall-Leutnant Franz von Werneck had 30 battalions and 24 squadrons near Günzburg. Kienmayer's command near Ingolstadt consisted of 19 battalions and 34 squadrons. Unwisely, Mack decided to defend Ulm, instead of trying to escape the approaching French army.

Mack reacted by sending Feldmarschall-Leutnant Franz Xavier Auffenberg with only 6,000 men to stop the French. Murat and Lannes crushed the hapless Auffenberg at the Battle of Wertingen, inflicting losses of 400 killed and wounded on the Austrians and capturing 2,900 soldiers and six cannons. The next day, General of Division Jean-Pierre Firmin Malher's VI corps division attacked General-Major Konstantin Ghilian Karl d'Aspré's 7,000 troops in the Battle of Günzburg. The Austrians suffered 2,000 casualties while the French lost 700 soldiers.

Napoleon placed Davout and Bernadotte at Munich to guard against General Mikhail Kutuzov's Russian army and Kienmayer's troops. The emperor sent Soult west to Memmingen, south of Ulm. Murat, Lannes, Ney, Marmont, and the Imperial Guard moved directly west toward Ulm. At this time, Ney's corps was still on the north bank. On 11 October, when Murat ordered Ney to bring his corps to the south bank, Ney furiously protested but was overruled. In consequence, Mack and Prince Schwarzenberg with 25,000 troops fell upon General of Division Pierre Dupont's solitary division in the Battle of Haslach-Jungingen that day. Dupont's 5,350 infantry, supported by General of Division Jacques Louis François Delaistre de Tilly's 2,169 cavalry fought the Austrians to a standstill. Dupont's force was mauled, losing 2,400 casualties, plus 11 guns and 2 eagles captured. Austrian losses numbered 4,100 killed, wounded, and captured.

More important, Mack was wounded in the fight and, with his force, "tamely returned to Ulm that night." On 12 October Mack reorganized his army into four corps under Schwarzenberg, Werneck, Jellačić, and Feldmarschall-Leutnant Riesch. The units were organized similar to the French corps, except that Mack constantly shuffled the component units. That day, Mack issued a flurry of orders, each set countermanding the previous instructions. In sum, he ordered Jellačić to march south to the Tyrol, Schwarzenberg to hold Ulm, and Werneck to move to Heidenheim an der Brenz followed by General-Major Johann Ludwig Alexius von Loudon's division of Riesch's corps. This was followed by a council of war at which Mack decided to send Riesch along the Danube to destroy all the bridges. In one speculative account, the real reason Mack sent Jellačić to the Tyrol was to get rid of Mayer, who led a brigade. Historian Frederick Kagan surmised that Mack was either confused or he deliberately scattered his army to give it a better chance to escape. In any case, Mack soon issued a new set of orders which were similar to the last set. Riesch set out with his command on the 13th, marching on water-logged roads in the direction of Elchingen.

On 13 October several French corps marched west on the south side of the Danube. Napoleon still hoped to encircle Mack's forces south of the river. He seemed unaware of the possibility that the Austrians could get away on the north bank. That day, Napoleon heard from Ney that only Dupont's division and some cavalry occupied the north bank in force. The French emperor ordered Ney and Marshal Joachim Murat to shift their forces to the north side of the river the next day. Also on the 13th, Soult wiped out General-Major Karl Spangen von Uyternesse's brigade in the Battle of Memmingen, capturing 4,600 men at the cost of 16 casualties.