Battle of Bar-sur-Aube

Macdonald attempted to slow Schwarzenberg's grand army at Bar-sur-Aube, but the French forces, outnumbered, were repulsed after violent fighting. The enemy, well organized with overwhelming superiority in numbers and artillery, retook this strategic position, opening the way toward Troyes and the Seine.

After allied defeats during the Six Days' Campaign and at Montereau, the coalition reorganized its lines. Macdonald was charged with defending Bar-sur-Aube, as the town commanded access to the Troyes region and communication with the east. Despite Napoleon's orders, coordination between marshals remained fragile and reinforcements were slow to arrive.

Macdonald established a defensive line on the west bank of the Aube, but allied assaults by Wrede's Bavarians, Barclay's Russians, and Austrians overwhelmed French lines. Superiority in artillery and progressive envelopment forced Macdonald's retreat in the evening, in good order but without possibility of counterattack.

The loss of Bar-sur-Aube allowed the Allies to regain initiative in the northeast and directly threaten Troyes and Nogent. Although losses were high on both sides, the French defeat reinforced the impression of progressive encirclement. Napoleon, forced to maneuver rapidly elsewhere, could not concentrate forces to stop all breakthroughs.