Battle of Auerstedt
Threatened by the French advance, on 12- 13th October the majority of the Prussian army (ca. 55,000 soldiers) under the Duke of Brunswick had begun to retreat with the aim of regrouping south of Leipzig. On the day of the battle, at least 55,000 Prussian soldiers and 230 cannons were nearing Auerstedt, whilst Davout and his circa 25,000 troops were advancing north. The two sides come into contact at the village of Hassenhausen, where a fierce battle erupted.
Despite outnumbering the French, the Prussians were initially reluctant to press their advantage. The Prussian commander, the Duke of Brunswick was mortally wounded early on in the battle, quickly followed by several other key Prussian leaders, which severely hindered the conduct of operations. Without clear direction from above, the battle degenerated into a free fight. A state of equilibrium occurred with both sides sustaining major losses in the opposing gun battle.
Davout appealed to Bernadotte, who was nearby, for assistance but was ignored. In the late morning, reinforcements arrived for both sides . Whereas as the arrival of French troops under the command of Morand enabled a general attack to take place, the Prussian reinforcements were less effective. Deployed somewhat erratically, they only served to delay the French advance. Eventually in the afternoon, the Prussian king, Friedrich Wilhelm III, took over as commander as his right flank came under heavy fire. Despite possessing strong reserves (14 battalions, 5 squadrons and 3 batteries of fresh troops), the king refused to authorize their engagement to support his flank, a move which proved to be fatal. By not using his advantage in numbers, the French were able to push on and occupy the high ground on both sides of the Prussian, leaving them caught in the crossfire.
With both Prussian flanks under serious threat and disintegrating, Friedrich broke off the battle and ordered a withdrawal towards Weimar, hoping to re-join Hohenlohe and Rüchel’s forces, which he believed were still intact. The retreat proceeded in good order until the evening when the army ran into Hohenlohe’s fleeing forces from Jena. Chaos ensued, resulting in a disorderly retreat. The French III corps pursued and harassed them into the early evening, but their numbers were too low and too exhausted to inflict serious causalities on the fleeing Prussians, who escaped north.
The French victory was hard-won – around 258 officers and 6,794 rank and file were wounded or killed in the battle – but was nevertheless impressive. Upon hearing news of Davout’s success, Napoleon initially refused to believe the report, claiming that “your Marshal must be seeing double!” (a reference to Davout’s poor eyesight). As it became clear Davout had fought the larger battle, Napoleon slowly came to realise that it was not himself, but in fact Davout who had routed the main Prussian army, and with just 26, 000 men too. Davout would receive Napoleon’s praise but his victory would also be side-lined in favour of Napoleon’s victory at Jena. Indeed, Napoleon increasingly viewed events at Auerstedt as simply the right wing of his forces at Jena, rather than a separate battle.