He then served in the War of the Fourth Coalition during the Prussia and Poland campaigns, and fought at Jena. He was then seconded to the 3rd Dragoon Division under 's command. He was promoted "Général de division" on 14 May 1807 and commanded the 1st Dragoon Division at the Battle of Heilsberg; he suffered battle wounds at Friedland, where his division was supporting the right flank of Marshal Victor's I Corps.