On 17 October 1806, the 9th Light Infantry fought in the Battle of Halle as part of Marie François Rouyer's brigade. Dupont's division was part of Marshal Jean-Baptiste Bernadotte's I Corps. The French inflicted 5,000 casualties on the Prussians while only sustaining losses of 800 killed and wounded. Meunier was wounded in the chest on this day. His regiment lost three officers and a number of men in the Battle of Waren-Nossentin on 1 November. Dupont's division was held in reserve at the Battle of Lübeck on 6 November. The I Corps fought in the Battle of Mohrungen on 25 January 1807. Dupont's division was involved in a skirmish at Braniewo (Braunsberg) on 26 February. The I Corps under Claude Perrin Victor fought at the Battle of Friedland on 14 June 1807. At Friedland, Dupont's division performed noteworthy service in breaking the Russian center.