In which battle in 1806 did Napoleon decisively defeat the Prussian army?

In which battle in 1806 did Napoleon decisively defeat the Prussian army? The Battle of Jena. Fought on 14 October 1806, the battle was a major French victory during the War of the Fourth Coalition.

Napoleon’s main force defeated a larger Prussian army near Jena in Saxony, while Marshal Louis-Nicolas Davout defeated another Prussian force at nearby Auerstedt on the same day. The two victories shattered Prussia’s military resistance and opened the road to Berlin.

A common mix-up is to treat Jena as the only battle of that day. Jena was Napoleon’s personal victory, but Auerstedt was equally important and was won by Davout against the principal Prussian army. The campaign exposed the weaknesses of Prussia’s aging military system and led to sweeping reforms after the defeat.