The next significant engagement came in 1809, during the War of the Fifth Coalition, against Austria. The 10th Cuirassiers were again a part of General Guiton's 2nd Brigade of the 2nd Heavy Cavalry Division, now under the command of General Saint-Sulpice, who had taken divisional command following the death of d'Hautpoul in 1807. The regiment, numbering 4 squadrons and a complement of 610 men, saw action at the Battle of Aspern-Essling, where Colonel Lhéritier bravely led from the front and received a bullet wound to the right shoulder and had a horse shot under him. Six weeks later, at the Battle of Wagram, the 10th Cuirassiers saw brief combat and had only one officer wounded. The next engagement for the regiment came on 11 July at the Battle of Znaim. There, Colonel Lhéritier was again noted for his bravery, as he led his men into action and in the process received a severe wound at the head. His actions during the campaign of 1809 were regarded very highly and on 21 July 1809, he was promoted to Brigadier General.