The battle of Teugn-Hausen (19 April 1809) was the first large scale battle during the Franco-Austrian War of 1809 (Fifth Coalition) and saw the main Austrian army under Archduke Charles fail to take a chance to trap Marshal Davout's isolated 3rd Corps. That isolation had come about while Marshal Berthier had command of the French and Allied armies in Germany. He has misunderstood Napoleon's instructions, and sent Davout east to Regensburg, well in advance of the rest of the army. By the time Napoleon turned up on 17 April Davout was approaching Regensburg, while much of the rest of the French army was around forty miles further west. When Napoleon did reach Berthier's headquarters, one of his first actions was to send a series of messengers to Davout ordering him to cross to the south bank of the Danube and then march west to join the rest of the French army.
Early on the morning of 18 April Davout received these orders from Napoleon, but his corps was still divided by the Danube. He decided to wait until his rearguard had crossed the river before leaving Regensburg, and so for most of the 18th Davout was stationary. Elsewhere the Bavarian troops of Marshal Lefebvre's 7th Corps were beginning to move towards Neustadt.
On the Austrian side the main army, under Archduke Charles, had crossed the Isar at Landshut on 16 April, and advanced slowly towards the Danube. By the night of 18-19 April Charles was at Rohr, ten miles to the east of Neustadt and fifteen to the south of Regensburg. At first Charles intended to move a short distance north from Rohr, to Grossmuss and Oberschambach, a move of about five to six miles that would have put him across Davout's line of march. This first plan may well have led to a major Austrian victory, placing the entire army between Davout's isolated corps and Lefebvre's scattered divisions, but it was quickly abandoned.
A French messenger was captured, carrying a message from Lefebvre to Davout. This announced that he had sent one division to a position half way between Neustadt and Rohr, and was ready to help Davout if he was attacked. The Austrians took this to mean that Davout was going to remain static around Regensburg for another day, and Charles decided to modify his plan. This time the entire army would move north-east from Rohr in an attempt to catch Davout much closer to Regensburg. The Austrian left wing was to pass through the villages of Hausen and Teugn on its way towards the Danube.
It was this new plan that allowed Davout to escape from the Austrian trap, and that set the scene for a series of French victories that would end with the Austrians forced to abandon the south bank of the Danube, exposing Vienna to French occupation. The central flaw in the Austrian plan was that Davout had no intention of staying at Regensburg for another day. By 5am on 19 April the French were on the road, moving in three parallel columns along some of the same roads that the Austrians were intending to use. The right-hand column, nearest to the Danube on the best road, consisted of the slower moving baggage and artillery trains. The centre and left columns contained Davout's four divisions, with Gudin and Friant on the left and Morand and St. Hilaire in the centre.
The Austrians didn't begin to move until after 6am. This meant that by the time the first tentative contacts were made between the two sides Davout's right column had already escaped from the trap. At about 8.30am, when the French first realised that the Austrians were on their left flank, Morand had already passed Teugn and Gudin was only a little further to the east. Davout ordered these two divisions to quicken the pace of their march, and they too slipped out of the Austrian trap. This just left St. Hilaire in the centre, Friant in the left column, and Montbrun's small force on the left flank.
For a short time there was a chance that these two French divisions would have to face two Austrian corps - Feldmarschalleutnant Prinz Freidrich Hohenzollern-Hechingen (known as Hohenzollern)'s III Corps and Rosenberg-Orsini's IV Corps, but after a few inconclusive skirmishes at around 9am Charles decided to send IV Corps east, still unaware that Davout's main force was passing by him to the north.
The central clash of the day thus involved Hohenzollern, St. Hilaire and Friant. Hohenzollern began the day by marching north from Rohr to Hausen, which quickly fell into his hands. His view north was blocked by a wooded ridge, the Hausnerberg. After his early success Hohenzollern continued to move north, with Lusignan's brigade on his right crossing the ridge and Vokassovich on his left advancing through the village of Roith. Unsure of Davout's location, Charles kept his reserve of 12 grenadier battalions at Grub, two miles to the south-east of Hausen.
The main part of the battle took place on the wooded hills between Hausen and Teugn. The two towns sat in parallel valleys, linked by a road running through a small gap in the hills. Two main ridges dominated - the Buchberg, nearest to Teugn, and the Hausnerberg, just to the south-east. The two ridges were separated by a shallow valley.
As the two Austrian columns advanced towards Teugn they finally ran into major French forces. The first clash was between Lusignan's skirmishers and Gudin's rearguard, but Gudin's men were soon replaced by the five regiments of St. Hilaire's division. As soon as he realised that the French were present in some strength Lusignan moved his few immediately available troops onto the Buchberg, and ordered the two nearest infantry regiments onto the Hausener Berg.
Davout responded by throwing his nearest available troops, the 3rd Ligne, up the Buchberg in skirmish order. They were repulsed, but the 57th Ligne arrived soon after this, and pushed the Austrians off the hill. Lusignan responded in turn by ordering his two regiments to attack the 57th and for some time the French were under heavy pressure. This only ended when Davout ordered the 10th Léger, supported by the 72nd and 105th Ligne, up the hill towards Roith, on the Austrian left.
Lusignan was now under attack on three flanks, by the troops at Roith, in front by the 57th and on his right by the leading elements of Friant's division. He was forced to retreat, followed by the 3rd and 57th Ligne. After a desperate battle in the woods on the Hausnerberg, Lusignan's men were forced to retreat back towards Hausen, carrying their wounded commander with them. The Austrians were also in trouble on their left, where the troops around Roith had been repulsed or captured.
During this fighting the rest of Hohenzollern's corps had remained inactive, but now, with Lusignan retreating out of the troops back towards Hausen, GM Fürst Alois Liechtenstein's brigade was thrown into the fray. By the time the Austrians were ready to attack the new French positions in the woods the 3rd and 57th Ligne had been replaced by two new regiments, the 72nd and 105th, and more of Friant's men were arriving on the scene.
Liechtenstein's first attack ran into trouble in the trees, and so he led a second wave of troops, from Infantry Regiment No.23 (Würzburg) into battle in person, but this attack also failed. Liechtenstein himself was injured in the fighting. Finally Hohenzollern attacked with his last two infantry regiments, but by 3pm this attack had also failed (Liechtenstein's brother Moritz, commanding one of the two regiments, was amongst the wounded). After the failure of this attack Hollenzollern sent a note to Charles informing him that his attacks on the woods had failed and that he was retreating behind Hausen.
Even now Charles remained passive, and didn't send any of his reserves into action until around 5pm. This final attack involved only four of his twelve grenadier battalions and four squadrons of cavalry. Charles demonstrated his own personal bravery by accompanying the attack himself, but it too failed at the edge of the woods.
The battle was finally brought to an end by a violent storm that drenched the battlefield. Both sides had suffered heavy casualties during the day, concentrated in the comparatively small elements of each army to be directly involved (around 17,000 on each side). The Austrians suffered just under 5,000 casualties, the French somewhere between 2,400 and 4,400. In the aftermath of the battle Davout's men were able to complete their march west, reuniting with the rest of Napoleon's army. The Austrians were demoralised by the day's fighting. That night Charles began to draft new orders that made it clear the invasion of Bavaria was over. Finally aware that Napoleon was now in direct command of the Allied armies, he would appear to have lost his nerve. The events of the next few days, beginning with Napoleon's first counter-attack at Abensberg, would only serve to further demoralise him.