Battle of Montmirail

The day after Champaubert, Napoleon turned against Sacken's and Yorck's forces advancing separately toward Paris. He rapidly concentrated his troops and struck at Montmirail. Fighting was intense but arrival of the Imperial Guard and French tactical superiority led to victory. The Allies retreated in disorder, abandoning men and equipment.

The coalition, believing the French army weakened after La Rothière, advanced in disorganized fashion. Napoleon exploited these errors. Montmirail was at the crossroads of strategic roads to Château-Thierry and Paris. By dividing and attacking enemy corps separately, he reversed the balance of forces. Fighting demonstrated the liveliness of the imperial army despite reduced numbers.

Napoleon attacked with infantry and artillery in the center while Ney enveloped the enemy right. Mortier, with the Guard, fixed the left wing. The objective was to separate Sacken and Yorck. Despite stubborn resistance, the Russians were outflanked. Prussians arrived late and could not reverse the situation. French artillery played a decisive role in breaching the center.

This second consecutive victory confirmed Napoleon's tactical genius. The Allies were forced to suspend their advance on Paris. The battle severely weakened Sacken's Russian and Yorck's Prussian contingents. It sowed confusion in enemy high command. The Six Days' Campaign continued to create the illusion of an invincible French army.