on 14 February. On 11 February, Napoleon turned the bulk of his army west toward Montmirail. He hoped to catch and destroy Sacken's corps between his army on the east and MacDonald's corps to the west at Meaux. Sacken's soldiers made a night march east toward Montmirail. Though Yorck urged his ally to retreat toward Château-Thierry, Sacken remained unaware of his danger and determined to fight what he believed was a weak enemy force. In the event, MacDonald had broken the Trilport bridge over the Marne, preventing him from striking Sacken's corps from the west. Delayed by the muddy roads, Yorck's tired troops were approaching Montmirail from the north, but still out of touch with Sacken. Napoleon barely managed to interpose some French soldiers at an important road intersection between the two Allied corps. In the Battle of Montmirail, Napoleon with 10,500 men and 36 guns faced Sacken's 18,000 Russians at 11:00 am while the vanguard of Yorck's 18,000 Prussians appeared to the north. By 4:00 pm reinforcements raised the French total to 20,000 and Napoleon went over to the attack. Another historian credited Napoleon with 27,153 troops at Montmirail, while the Prussians believed that 24,000 French soldiers were present. During the early afternoon, the two armies engaged a bitter struggle over the village of Marchais-en-Brie south of the Montmirail-Meaux highway while Napoleon tried to break through Sacken's left wing near the highway. Meanwhile, Yorck's troops attacked from the north at 3:30 pm, only to be repulsed. Finally, the French infantry flushed Sacken's men out of Marchais into the open where they were ridden down by French cavalry. Yorck's belated intervention probably saved Sacken's corps, which retreated to the north that evening. Sacken's corps suffered 2,000 killed and wounded, plus 800 soldiers, 13 field guns, and six colors captured. Yorck sustained 900 casualties and French losses were around 2,000 men. Battle Forces Action On 11 February, Kaptzevich and Kleist turned around and marched back to Bergères. Blücher authorized Yorck and Sacken to withdraw via Château-Thierry toward Reims where his army would reassemble. MacDonald sent Antoine-Louis Decrest de Saint-Germain with part of his cavalry across the Marne to Coulommiers by a roundabout route. The remainder of his cavalry under Horace Sebastiani was unable to cross at La Ferté-sous-Jouarre because Sacken had broken its bridge. Napoleon launched his troops after the beaten Allies at 9:00 am on 12 February. Marshal Édouard Mortier