The Battle of Czarnowo on the night of 23–24 December 1806 saw troops of the First French Empire under the eye of Emperor Napoleon I launch an evening assault crossing of the Wkra River against Lieutenant General Alexander Ivanovich Ostermann-Tolstoy's defending Russian Empire forces. The attackers, part of Marshal Louis-Nicolas Davout's III Corps, succeeded in crossing the Wkra at its mouth and pressed eastward to the village of Czarnowo. After an all-night struggle, the Russian commander withdrew his troops to the east.