Campagne d'Allemagne
In 1799, d'Hautpoul commanded cavalry brigades under Ney, Lecourbe and Baraguey d'Hilliers in the rest of the campaign in northeastern Switzerland. In the German campaign of 1800, he served under Moreau and distinguished himself at the battles of Biberach and Hohenlinden, during which his heavy cavalry was instrumental in disrupting the Austrian infantry defenses.