Gudin's troops were on the move from Nauburg before 6:30am. By 7 am the 1st Chasseurs were stopped cold in their tracks outside of Poppel by Prussian cavalry and artillery. There was a heavy fog that had lifted just as they approached the village. Once Davout became aware of the Prussian force he ordered Gudin to deploy his force at Hassenhausen.

The present Prussian commander on the field was Schmettau and his division was actually under orders to proceed down the very road that Davout was on to block his advance in the Kosen Pass. While his troops were deploying to attack Hassenhausen, Blucher arrived with his cavalry and deployed on his left. Together they attacked Gudin's troops and pushed them back to the village.

Wartensleben arrived at 8:30am with Brunswick who ordered his infantry to the left flank and his cavalry to the right. The rest of the French cavalry arrived at 9 am and was placed on Gudin's left. Friant and the 12pr artillery arrived at 9:30am and moved in squares on Gudin's right. The advance of the French squares forced Blucher's cavalry back. Seeing no other option available he ordered his cavalry to attack. At this very moment two of Wartensleben's regiments attacked Hassenhausen.

Everything failed, three cavalry regiments were routed and the infantry fell back. At this critical point, Brunswick needed to take drastic action. Shortly before 10 am he ordered a full assault on Hassenhausen. By 10 am Brunswick was carried from the field mortally wounded along with Schmettau who was also badly wounded. With the loss of these two commanders the Prussian command broke down. The Prussian army was in danger of collapse.

Blücher's infantry and the Prince of Orange arrived about 10:30am and the King made his only decision of the day, to split Orange's command in two, half to each flank. On the French side Morand's Division arrived and was sent to secure Gudin's left. Davout could now see that the Prussians were wavering so at 11 am he ordered his infantry to counter attack. By noon Schmettau's center was broken and forced back over the Lissbach Stream, Blucher's cavalry was blown and Wartensleben was trying to reposition his troops. The Prussians realized all was now lost and the King ordered a withdrawal.

Napoleon initially did not believe that Davout's single Corps had defeated the Prussian main body unaided, and responded to the first report by saying "Tell your Marshal he is seeing double". As matters became clearer, however, the Emperor was unstinting in his praise. Bernadotte was severely censured and came within an ace of being dismissed on the spot — despite being within earshot of Auerstedt and within marching distance of Jena, he ignored his orders and did not fire a shot in either battle. Davout was made Duke of Auerstedt. Soult, the hero of Jena, was not so honoured, possibly because Napoleon judged it best for reasons of prestige to keep the glory for himself.

                                    

 

On the Prussian side, Brunswick had been mortally wounded at Auerstedt, and over the next few days the remaining forces were unable to mount any serious resistance to Murat's ruthless cavalry pursuit. Davout led his exhausted III Corps into Berlin on October 25th. Hohenlohe's force surrendered on October 28th, Blucher's on November 7th. Isolated Prussian resistance remained, but Napoleon's primary foe was now http://en.wikipedia.org/wiki/Russia - Russia , and the http://en.wikipedia.org/wiki/Battle_of_Eylau - Battle of Eylau awaited.

The battle proved most influential in demonstrating the need for liberal reforms in what was then still a very much feudal Prussian state and army. Important Prussian reformers like http://en.wikipedia.org/wiki/Gerhard_von_Scharnhorst - Scharnhorst , http://en.wikipedia.org/wiki/August_von_Gneisenau - Gneisenau and http://en.wikipedia.org/wiki/Carl_von_Clausewitz - Clausewitz served at the battle. Their reforms, together with civilian reforms instituted over the following years, began Prussia's transformation into a modern state, which would take the forefront in expelling France from Germany and eventually assume a leading role on the continent.

                                     http://upload.wikimedia.org/wikipedia/commons/9/9f/Battle_of_Jena-Auerstedt_-_Map01.jpg">

The http://en.wikipedia.org/wiki/Germany - German http://en.wikipedia.org/wiki/Philosophy - philosopher http://en.wikipedia.org/wiki/Georg_Wilhelm_Friedrich_Hegel - Georg Wilhelm Friedrich Hegel , who was then a professor at the http://en.wikipedia.org/wiki/University_of_Jena - University of Jena , is said to have completed his chef d'oeuvre, the http://en.wikipedia.org/wiki/Phenomenology_of_Spirit - Phenomenology of Spirit , while the battle raged. Hegel considered this battle to be "the end of the history", in terms of evolution of human societies towards what we would call the " http://en.wikipedia.org/wiki/Liberal_democracy - liberal democracy ". More on that in http://en.wikipedia.org/wiki/Francis_Fukuyama - Francis Fukuyama 's book: http://en.wikipedia.org/wiki/The_End_of_History_and_the_Last_Man - The End of History and the Last Man .

 

Today, every year thousands of participants of many nations are re-enact this battle in uniforms based on the original ones.

 

As you can see , a total defeat can be a good begin of a reformation.