On the 10 April 1809 an Austrian army of 150,000 men under the Archduke Charles crossed over the Inn River into Bavaria, achieving strategic surprise. Meanwhile, north of the Danube, Gdk (General der Kavalerie) Bellegarde with 50,000 troops marched south on Ratisbon iRegensburg). The Tyrol erupted in revolt against Bavaria and cut French communications with Prince Eugene's Italian based forces. Napoleon knew they were coming but had been expecting the attack on or after the I 5th and had lingered in Paris, not wishing to be seen as provoking the war.

Charles chose to concentrate most of his regular forces on the Danube, with secondary forces marching on Poland and Italy under the Archclukes Ferdinand and John respectively. His initial plan was to march from Bohemia to deal with Marshal Davout and to cut off the French forces in Northern Germany, but he had decided on a more cautious march up the south bank of the Danube. Davout, marching south of Ratisbon with 55,000 men, had detected this on the 27 March and advised Napoleon. The latter was not expecting a lightning strike from the ponderous Austrians and had left his chief of staff, Marshal Berthier, in charge of the theatre.

Unfortunately, due to fog, a communications disaster affecting the visual telegraph system led to a confusion of orders. Berthier was given the impression that he was to concentrate around Ratisbon rather than further from the border on the Lech River around Donauworth, over 100 kms west of Ratisbon. Davout, fully aware of the Austrian concentrations, was evading by marching south towards the main army but was ordered to countermarch on Ratisbon and would thus find himself isolated.

Deroi's Bavarian division was at Landshut around 50 kms south of Ratisbon guarding the Isar River and attempted to slow the Austrians to allow the French and Allied forces to concentrate. On the 16 April they were forced back and Charles achieved a classic Napoleonic "Central Position", although he was unaware of the precise French dispositions. They were actually scattered on a 120 km front with only a light cordon of Bavarians connecting Davout to the main forces.

The Austrian march had been slowed to around eight miles a day by heavy rain, giving Napoleon the opportunity to leave Paris on the 13 April and to arrive at Donauworth and the front on the 17. This was just in time to sort out the confusion at headquarters and plan a counteroffensive. This would start on the 19 against the Austrian rear as Charles headed north to Batisbon.

By 17 April Charles was still unsure how to bring the enemy to battle, and continued north for a crossing between Ratisbon and Ingolstadt. Here he could link up with Bellegarcle west of the Danube. The Austrian advance guard pushed the Bavarians back to the Albans River, while a light brigade under GM (General-Feldwachtmeister) Vecsay reached Eckmuhl.

On the night of the 17, Napoleon learned that the column coming up from Landshut was larger than expected and that Bellegarde was nearing his lines of communication. He deduced that Charles would attack Davout and hold the Bavarians on his left, hours before the Archduke thought of it himself towards noon on the 18. He decided that Marshal Massena should take the offensive towards the Austrian rear by way of Landshut, whilst the Bavarians held the centre for Davout to rejoin. He would then push Charles against the Danube and, unable to cross the 'demolished' bridge at Ratisbon, the Austrians would fold. However, Massena would fail to concentrate quickly and would only reach Pfaffenhausen, some 50 The detached French divisions crossed on the 18 as Bellegarde moved south-west. FZM (Feldzeugmeister) Kollowrath was left to prepare an assault on Ratisbon. The French could not blow up the massive bridge across the Danube, and by that evening had barely begun to concentrate.

Vecsay's patrols from Eckmuhl advised their commander that Davout had remained at Ratisbon on the 18. Charles responded by ordering his main forces to intercept the Marshal before he could join the Bavarians. In the meantime, the Archduke Louis and his 5th Korps would hold the three Bavarian division's attention where they were massing west of the Abens River. The Austrians had just been given the opportunity to destroy the finest Corps in French service, under the best Marshal: could they get their blow in quickly enough, before the rest of the enemy army could respond?

More Battle of Teugen-Hausen 19 April 1809

Introduction and Background
Preparation for Battle
The Battle of Teugen-Hausen
Order of Battle
The Wargame