Battle of Auerstedt

On the same day as Napoleon at Jena, Davout faced the bulk of the Prussian army. Despite numerical inferiority of roughly one to two, he held all day thanks to the exceptional discipline of his troops. General Brunswick was mortally wounded, the Prussian chain of command collapsed, and Davout turned a defensive position into a brilliant victory.

On 14 October 1806 Napoleon engaged at Jena what he believed to be the main Prussian army. He was mistaken: the main body was marching on Auerstaedt, where King Frederick William III was present in person, effective direction resting with the Duke of Brunswick. Facing them stood Davout with his III Corps alone: some 26,000 men, 1,400 cavalry and 44 guns against about 66,000 Prussians, 14,000 cavalry and 230 pieces. Convinced they faced only a rearguard, the Prussians attacked. Davout chose to hold and counter-attack rather than give way.

Davout deployed Gudin then Friant in a defensive line on the heights, in fog that hampered reconnaissance. The Prussians launched repeated but poorly coordinated assaults, which III Corps repelled one after another: their linear tactics, lacking any link with skirmishers, never brought their numerical superiority to bear. Brunswick was mortally wounded early in the action, leaving the Prussian command without direction. Around midday Morand's division arrived; Davout went over to the offensive and broke the centre. Jomini would write that no day of the Revolutionary Wars had offered so disproportionate a struggle.

Auerstaedt, together with Jena, destroyed Prussian military power: the French entered Berlin on 25 October 1806 and occupied it for three years. Davout was made Duke of Auerstaedt, and his victory is often held to be greater than the one Napoleon won the same day a few leagues away. III Corps, formed at the camp of Boulogne, acquired a reputation as an elite formation that it kept until the end of the Empire.