Efforts by the French Revolutionary government to remove him from his command failed when his soldiers refused to give him up.

[3] His cousin, Alphonse Henri, comte d'Hautpoul, also served in the Napoleonic Wars, as a lieutenant in the Iberian peninsula, and was taken prisoner at the Battle of Salamanca.

[4] By contemporary accounts, d'Hautpoul was a big man, possibly taller than Joachim Murat, who was nearly six feet tall.

Endowed with broad shoulders and a big voice, he spoke the language of the common soldier, and led from the front.

[8] After his recovery, d'Hautpoul was given command of the heavy cavalry of the Army of Sambre-et-Meuse under General Paul Grenier.

When the French Directory abandoned the idea of an invasion of England, he was again deployed on the German front, this time as part of the Army of the Danube.

A few days later, after failing to lead a timely charge at the Battle of Stockach, he was suspended on orders of the Army commander, Jean-Baptiste Jourdan, who blamed d'Hautpoul for the defeat.

Acquitted by a court-martial in Strasbourg, d'Hautpoul resumed his duties at the end of July 1799, having missed the critical actions at the First Battle of Zurich.

[8] In 1799, d'Hautpoul commanded cavalry brigades under Ney, Lecourbe and Baraguey d'Hilliers in the rest of the campaign in northeastern Switzerland.

In the German campaign of 1800, he served under Moreau and distinguished himself at the battles of Biberach and Hohenlinden, during which his heavy cavalry was instrumental in disrupting the Austrian infantry defenses.

At Austerlitz, d'Hautpoul distinguished himself by leading his heavy cavalry into the Russian center at the Pratzen heights, breaking the infantry squares.

Transferred to the Corps of Marshal Bessières in December 1806, he again served under Murat in the maneuvers in East Prussia in the Winter of 1807.

[12] The next morning, the two armies of unequal strength faced each other across frozen fields fissured by ice-covered streams and ponds, which were in turn covered by snow and drifts.

No sooner had Augereau and VII Corps, plus St. Hilaire's division, sallied out when a sudden snow storm engulfed the battlefield.

Five thousand French soldiers fell in a matter of minutes and the entire engagement stood on the brink of disaster.

[13] To fill the breach left by Augereau's decimated corps, Napoleon ordered Murat's cavalry reserve, 80 squadrons of 10,700 cavalrymen, into action at 10:30 in the morning.

On the second charge, they broke the second formation of squares; at this point, Grouchy's men were forced back, but d'Hautpoul's cuirassiers pounded forward,[14] reaching the Russian reserve.

One of his regiments while fighting in an interval of the Russian army, was shot down and cut to pieces by the Cossacks; only eighteen of them escaped.