D'Aspré received a command in the army of Archduke Ferdinand Karl Joseph of Austria-Este and Karl Mack von Lieberich at the beginning of the War of the Third Coalition.
He led a brigade-sized unit of three and one-half infantry battalions and six cavalry squadrons.
When the army of Emperor Napoleon I of France reached the Danube on 6 October, Mack realized that his army was in danger of being cut off from Vienna.
At that time, he made the questionable decision to assemble the corps of Franz Jellacic, Franz von Werneck, and Karl Philipp, Prince of Schwarzenberg near Ulm, renouncing any idea of retreating south to the Tyrol.
On 8 October, he issued orders for his army to concentrate at Günzburg downstream from Ulm.
He hoped to put his troops in a position to sever Napoleon's supply line back to France.
At this time, Napoleon was only vaguely aware of the Austrian army's position.

On 8 October, Marshals Joachim Murat and Jean Lannes encountered Franz Xavier Auffenberg's division at the Battle of Wertingen.
The French crushed the outnumbered Austrians and drove the survivors west to Günzburg.
The next day, Mack and Ferdinand drew up their troops facing east on the south bank of the Danube near Günzburg.
Mack deployed d'Aspré and a light force that included Tyrolean Jägers to hold and scout the north bank.
Unknown to Mack, Marshal Michel Ney sent one of his divisions to seize the Günzburg bridges from the north that morning.

Jean-Pierre Firmin Malher formed his 3rd Division of the VI Corps into three columns and marched south on 9 October.
The western column blundered into a marsh, while the eastern column was badly delayed.
The centre column marched straight for Günzburg and collided with d'Aspré's troops.
As soon as the soldiers in Günzburg heard the firing, they immediately destroyed the bridges.
Unfortunately, this left d'Aspré with the French in front of him and an unbridged river behind him.
He surrendered with 200 Jägers and two cannons.

Warned by d'Aspré's scouting force, the Archduke Charles Infantry Regiment Nr.
3 and 20 cannons mounted a vigorous defence, bringing Mahler's attack to an abrupt halt at the river bank.
At this point, Mack ordered Ignaz Gyulai to rebuild the bridge on the east side of town and cross to the north bank.
Mack still dreamed of crossing the Danube and advancing on Giengen and Nördlingen.
No sooner did Gyulai have the bridge ready, when the tardy western column appeared and captured the span, winning the battle for the French.

Mack later claimed that d'Aspré failed to report his contact with the French, though this may be an attempt at self-justification.
Ney interrogated his prisoner d'Aspré and reported to Napoleon that the Austrian army was falling back to Biberach an der Riß.
This was not true, but it is not clear whether d'Aspré deliberately misled his captor or if he was only guessing what Mack's intentions were.
The campaign ended in disaster for Austria when Mack capitulated with 25,000 troops at Ulm on 20 October, Werneck surrendered his remaining 6,000 men on 18 October, and the 4,600-strong garrison of Memmingen also ran up the white flag.
A total of almost 50,000 Austrians became prisoners in the fighting.
D'Aspré received a command in the army of Archduke Ferdinand Karl Joseph of Austria-Este and Karl Mack von Lieberich at the beginning of the War of the Third Coalition. He led a brigade-sized unit of three and one-half infantry battalions and six cavalry squadrons. When the army of Emperor Napoleon I of France reached the Danube on 6 October, Mack realized that his army was in danger of being cut off from Vienna. At that time, he made the questionable decision to assemble the corps of Franz Jellacic, Franz von Werneck, and Karl Philipp, Prince of Schwarzenberg near Ulm, renouncing any idea of retreating south to the Tyrol. On 8 October, he issued orders for his army to concentrate at Günzburg downstream from Ulm. He hoped to put his troops in a position to sever Napoleon's supply line back to France. At this time, Napoleon was only vaguely aware of the Austrian army's position.
On 8 October, Marshals Joachim Murat and Jean Lannes encountered Franz Xavier Auffenberg's division at the Battle of Wertingen. The French crushed the outnumbered Austrians and drove the survivors west to Günzburg. The next day, Mack and Ferdinand drew up their troops facing east on the south bank of the Danube near Günzburg. Mack deployed d'Aspré and a light force that included Tyrolean Jägers to hold and scout the north bank. Unknown to Mack, Marshal Michel Ney sent one of his divisions to seize the Günzburg bridges from the north that morning.
Jean-Pierre Firmin Malher formed his 3rd Division of the VI Corps into three columns and marched south on 9 October. The western column blundered into a marsh, while the eastern column was badly delayed. The centre column marched straight for Günzburg and collided with d'Aspré's troops. As soon as the soldiers in Günzburg heard the firing, they immediately destroyed the bridges. Unfortunately, this left d'Aspré with the French in front of him and an unbridged river behind him. He surrendered with 200 Jägers and two cannons.
Warned by d'Aspré's scouting force, the Archduke Charles Infantry Regiment Nr. 3 and 20 cannons mounted a vigorous defence, bringing Mahler's attack to an abrupt halt at the river bank. At this point, Mack ordered Ignaz Gyulai to rebuild the bridge on the east side of town and cross to the north bank. Mack still dreamed of crossing the Danube and advancing on Giengen and Nördlingen. No sooner did Gyulai have the bridge ready, when the tardy western column appeared and captured the span, winning the battle for the French.
Mack later claimed that d'Aspré failed to report his contact with the French, though this may be an attempt at self-justification. Ney interrogated his prisoner d'Aspré and reported to Napoleon that the Austrian army was falling back to Biberach an der Riß. This was not true, but it is not clear whether d'Aspré deliberately misled his captor or if he was only guessing what Mack's intentions were. The campaign ended in disaster for Austria when Mack capitulated with 25,000 troops at Ulm on 20 October, Werneck surrendered his remaining 6,000 men on 18 October, and the 4,600-strong garrison of Memmingen also ran up the white flag. A total of almost 50,000 Austrians became prisoners in the fighting.
Konstantin Ghilian Karl d'Aspré