Promoted to captain in 1810, he further served Mouton, by now count of Lobau, as "aide-de-camp" and he accompanied him into Russia where he served at Vitebsk, Smolensk and Borodino. In October 1812 he was made "aide-de-camp" of general Narbonne and was present at Krasnoi and the crossing of the Beresina. Promoted to major, he served in the personal protection detail of the emperor during the retreat. De Castellane was promoted to command of the 1st Regiment Garde d'Honneur in June 1813. During the German campaign he fought at Dresden.