Rottembourg served as an adjutant general in the Imperial Guard during the French invasion of Russia in 1812, but was sent back to France to organize part of the Imperial Guard. He performed this task with such success that he was awarded the Commander's Cross of the Legion of Honor on 13 May 1813. At the Battle of Bautzen on 20–21 May 1813, Rottembourg commanded a brigade in Pierre Barrois' 2nd Young Guard Division. The brigade included two battalions each of the 1st and 2nd Tirailleur Regiments. The 1st Tirailleurs numbered 27 officers and 1,031 rank and file. During the early fighting on 21 May, Barrois' division was ordered to support the attack of Marshal Auguste de Marmont's corps in the center. Late in the afternoon, the massed divisions of the Imperial Guard were used to break the Allies' resistance.