Soon after the coup d'état of 18 Brumaire, the Guides, who had stayed in the south of France, were summoned to Paris and quartered in the Caserne de Babylone.

The cavalry of the Garde Consulaire – two squadrons of Grenadiers à Cheval and the company of chasseurs – was commanded by Chef de brigade Jean-Baptiste Bessières.

It crossed the Great St Bernard Pass and was heavily engaged at the Battle of Marengo (14 June), losing 70 out of its 115 horses.

From 22 March 1803, when summer training (travail d'été) began, the men were to parade on horseback every Monday and Thursday at 7.30 a.m. precisely on the Champ de Mars.

The regiment and the Mamluks greatly distinguished themselves at the Battle of Austerlitz (2 December), where two squadrons and the Mamluks were led to the charge by Napoleon's senior aide-de-camp, General Jean Rapp, inflicting heavy casualties on the Russian Imperial Guard and capturing Prince Repnin, the commander of the Chevalier Guard.

At Austerlitz, the Chasseurs suffered 19 officer casualties, including Morland, killed, and three squadron commanders wounded.

At Eylau (8 February 1807), the regiment took part in Joachim Murat's great charge of 80 squadrons, which relieved the pressure on the French centre at the crisis of the battle.

He had recently been promoted general (30 December 1806), but having no command, he asked to be allowed to lead his old regiment and fell at their head.

On 28 November, Napoleon, engaged in pressing the retreat of Sir John Moore towards Corunna, rode ahead of his army into the village of Valderas, which the British had abandoned just two hours previously.

That it had been imprudent was proved next day (29 December) when General Lefebvre-Desnouettes caught up with the British rearguard, forded the River Esla and drove in their pickets, only to be counter-attacked by Lord Paget (the Uxbridge of Waterloo fame), who led his men under cover of the houses of Benavente to assail the French flank.

Thiry was made général de brigade in the line and, on the 13th, Daumesnil and Hercule Corbineau were promoted majors.

At Wagram, the Guard cavalry supported the right flank of MacDonald's great column which struck the decisive blow.

The regiment suffered at Wagram (6 July), having 5 officers killed and 10 wounded, including the two newly promoted majors, each of whom lost a leg.

To replace Corbineau and Daumesnil as majors, the regiment received Colonel François d'Haugéranville (6 August) and General Baron Exelmans (24 December).

On 6 May 1812, General Lefebvre-Desnouettes, who had escaped by breaking his parole, returned from his captivity in England and resumed command of the regiment.

But on 25 October, the day after the Battle of Maloyaroslavets, two squadrons, escorting the Emperor on a reconnaissance, were sharply engaged and had 4 officers wounded.