Marcognet fought in Baptiste Pierre Bisson's division at the Battle of Guttstadt-Deppen on 5 and 6 June 1807. In this action, Ney's 17,000 troops executed a brilliant rear guard action against over 63,000 Russians. Marcognet participated in the Battle of Friedland on 14 June. Bisson's division formed Ney's left flank. After initial success, a massed Russian cavalry charge against Bisson's left flank stopped Ney's attack cold. However, Claude Perrin Victor's corps drove back their enemies, allowing Ney's troops to rally and capture the town of Pravdinsk (Friedland).