The battle of Halle (17 October 1806) was a French victory over the intact Prussian reserve army in the aftermath of the battles of Jena and Auerstädt.
The Prussian reserves, under Prince Eugen of Württemberg, had moved to Halle on the River Saale just at Napoleon was invading Saxony from the south. He was still there when Napoleon defeated the Prussian flank guard at Jena and Davout defeated the main army at Auerstädt, both on 14 October. The surviving Prussian began to retreat north towards Magdeburg, passing to the west of Haale.
On the French side Marshal Bernadotte had ignored his orders and spent 14 October marching between the two battlefields. He was reprimanded by Napoleon, only narrowly avoided a court-martial, and was now determined to restore his reputation during the pursuit. He had a fresh corps of just over 20,000 men at his disposal, although not all of them fought at Halle - most of the fighting on the French side was carried out by the 6,700 men of Dupont's division and the corps cavalry. Napoleon decided to use part of his army to closely pursue the Prussians, while the rest of it was ordered to advance a little further to the east, heading north alongside the Prussian line of retreat in an attempt to cut them off. Bernadotte's corps was the only fresh unit available for this flanking force.
Württemberg commanded a force of 11,350 infantry, 1,675 cavalry and 38 cannon. Halle was not an easy place to defend. The town was located on the eastern side of the Saale River, but wasn't strong fortified. Württemberg decided to position his main army south of the town, on the east bank of the river. A force of infantry under General Johann Freiherr von Hinrichs was given the task of defending the river crossing, which considered of a causeway with two bridges. A little further west a dragoon regiment was positioned at the village of Passendorf.
The fighting began at 8am when Bernadotte's cavalry pushed the Prussian dragoons out of Passendorf. There was then a two hour while he waited for his infantry to reach the area. First into action was part of General Dupont's 1st Division. The 32nd Line and 9th Light Infantry attacked Hinrichs' position, broke through his centre and captured the bridges. Hinrichs was forced to surrender.
Dupont advanced into the undefended town of Halle, and occupied a position on the south of the town, facing the Prussians. Skirmishers were deployed against the Prussians, and Dupont then waited for reinforcements to reach him.
Realising that he could no longer hold his position at Halle, Württemberg decided to retreat north/ north-east towards Dessau. Instead of withdrawing east and then turning north, Württemberg decided to move north past the town.
This gave the French a chance to attack the Prussian army in the flank as it marched past the town. Dupont's division was now reunited in Halle, and Rivaud's second division had also begun to arrive. Rivaud took up a position on Dupont's right. Dupont then attacked east out of Halle. The Prussian line was soon split in two, with part retreating north towards Dessau and part north-east towards Bitterfeld. The French pursued for some way, but the Prussians managed to retreat in good order and Bernadotte's attention soon returned to the main Prussian army, further west.
Bernadotte's victory at Halle had effectively destroyed the Prussian reserve. Württemberg lost 5,000 men, almost half of his original force. This meant that his reserve corps was no longer available to act as the core of a reformed Prussian army, or to play a significant part in the upcoming siege of Magdeburg (20 October-11 November 1806).