In 1805, Emperor Napoleon Bonaparte appointed Marshal Joachim Murat to command all the cavalry divisions that were not directly attached to the army corps.

Under Murat, the Cavalry Reserve played a prominent role in the destruction of the Prussian armies after the Battle of Jena-Auerstedt in 1806.

[2] On 8 October 1805, at the Battle of Wertingen, Murat and Marshal Jean Lannes attacked an isolated Austrian division under General Franz Xaver von Auffenberg.

With the support of some V Corps infantry, Murat's horsemen rode down the helpless Austrians, inflicting losses of 400 killed and wounded, 2,900 prisoners, six guns, and six flags.

[4] Murat led his horsemen in a series of actions between 16 and 18 October before securing the surrender of General Franz von Werneck's Austrian corps.

[13] At the Battle of Eylau on 8 February 1807, Murat led a grand charge of 80 squadrons of cavalry, altogether 10,700 horsemen.

The French cavalry suffered 1,500 casualties but they badly disrupted the Russian lines at a critical point in the battle.

Nansouty led the I, General Louis-Pierre Montbrun the II, Grouchy the III, and La Tour-Maubourg the IV Cavalry Corps.