By 1803, the Napoleonic Wars began to threaten Denmark, which had remained neutral. Ewald was again in the vanguard of the military forces, responsible for the defense of the Duchy of Holstein, which represented Denmark's southern frontier. In 1806, after the Prussian loss to French forces in the Battle of Lübeck, Prussian forces attempted to cross the border to escape the French. The French, believing they had done so, demanded the right to cross the border in pursuit. Ewald, in a bold bid to speak directly with the French commander, Joachim Murat, jumped a horse over a ditch and convinced a French officer to bring him to Murat. Murat refused to believe Ewald's assertion that Prussians had not crossed the border, and threatened to kill him. Murat also refused to give Ewald an escort back to his own lines; Ewald had some difficult returning due to the unsettled conditions in the area. The incident resulted in the removal of French forces from Danish territory. Napoleon also insured that Danish neutrality was respected.