commanded the pursuit on the main highway while Napoleon personally led another column farther west through Rozoy. The French emperor ordered MacDonald to seize the bridge at Château-Thierry. At dawn on 12 February, Sacken's corps passed through Yorck's lines near Montfaucon. Sacken dropped off a brigade under General Heidenreich that consisted of the Tambov and Kostroma Regiments. Friedrich von Katzler's advance guard stood at Montfaucon with the 1st and 7th Prussian Brigades and the Reserve cavalry of Georg Ludwig von Wahlen-Jürgass in support. Mortier marched to Fontenelle-en-Brie with the 2nd Old Guard Division under Charles-Joseph Christiani, the 1st Voltiguer Division under Claude Marie Meunier, and the Gardes d'Honneur cavalry. Napoleon had Saint-Germain with 2,400 cavalry and Louis Friant's 1st Old Guard Division. At 1:00 pm, Mortier's advance encountered Katzler's Prussians near Viffort and the Caquerets Hills. Katzler's 1st and 2nd East Prussia Infantry Regiments overlooked a stream. The position was attacked by two battalions of Old Guard Foot Chasseurs and Napoleon's duty squadrons led by Claude-Étienne Guyot. Katzler withdrew when the French began turning his flanks. Farther along the highway, the French found Heinrich Wilhelm von Horn's 7th Brigade barring their advance. The 2nd Silesian and Leib Grenadier Battalions defended the right flank while the Leib Regiment held the left flank. While the French forces began to deploy in front, a large force of cavalry under Marshal Michel Ney began to maneuver around the Prussian left flank. These were four divisions of elite cavalry under Pierre David de Colbert-Chabanais, Jean-Marie Defrance, Charles Lefebvre-Desnouettes, and Louis Marie Levesque de Laferrière. At this time, Napoleon sent 200 grenadiers to seize the hamlet of Petite-Noue. Mortier launched six battalions under Christiani in a frontal attack. Aware that he would have to fight with a river at his back, Yorck ordered his wagon train to cross to the north bank of the Marne. Yorck ordered Jürgass to move 3,000 Reserve cavalry from the highway to the left flank to counter the French cavalry threat. They were joined by the Brandenberg Hussar Regiment under Friedrich von Sohr. Many of the Prussian cavalrymen were Landwehr - second class soldiers. Jürgass formed his horsemen in two ranks, with the Lithuanian and 1st West Prussian Dragoon Regiments in the first line. There was also a Russian dragoon regiment on hand. Defrance and Laferrière placed the Guard Dragoons in the first line and the Horse Grenadiers, cuirassiers, and horse