Morand's first campaign with III Corps was against Prussia in 1806. His division played a vital part in the battle of Auerstedt, where Davout's lone corps defeated a Prussian army more than twice their size. During the battle, Morand was wounded in the arm by a canister shot. Continuing to campaign into Poland, he fought at the capture of Custrin, the crossing of the Bug, and the battles of Czarnowo and Golymin, before being wounded again at Eylau.