The engagement of Bar-sur-Aube (24 January 1814) was a rearguard action during the French retreat from their frontiers early in the campaign of 1814, and saw Marshal Mortier hold off an attack by two Allied corps for a day, before being forced to retreat by superior numbers.
Early in the campaign Mortier and the Old Guard were sent south to Langres to support Marshal Victor on the French southern flank. Victory had retreated from Strassbourg without a fight, in order to avoid getting trapped on the border. He then abandoned Nancy, allowing the Allies to approach the Meuse. Mortier was unable to restore the situation, and was soon forced to retreat north-west to Bar-sur-Aube.
Mortier faced part of Schwarzenberg's Army of Bohemia. Two corps threatened his position at Bar-sur-Aube – 3rd Corps under Count Giulay (also spelt Gyulay or Gyulai) and 4th Corps, under the Crown Prince of Wurttemberg.
Mortier deployed his troops in curved line around Bar-sur-Aube.
In his rear he posted 1,200 men to guard the bridge at Dolancourt, north-west of Bar. To the west (right-rear) he posted two battalions of the Old Guard on a plateau between Proverville (just to the west of Bar) and Spoy, three miles further west.
To the south (on his right) he posted a reinforced battalion of the Old Guard and the Guard Chasseurs a cheval in Fontaine, a village about a mile and a half south of Bar.
Further south General Michel's 2nd Old Guard division was posted on the heights between Fontaine and Baroville.
In the centre General Friant's grenadier brigade and the 3rd Guard Cavalry Division (Laferriere) were posted north of the Aube, behind the Voigny stream, a tributary of the Aube that flowed into the river from the north-east.
On his left he posted a detachment in the village of Arrentieres, north-east of Bar, to watch the road towards Doulevant.
Well in advance of the main line Letort's brigade and four battalions from the 1st Division were posted in Colombe-les-deux-Eglises, about eight miles east of Bar, where the formed the French rear guard.
The Allies advanced in two columns. 4Th Corps (Austrian) was on the right, and advanced along the main road from Chaumont, heading west towards Bar-sur-Aube through Colombe-les-deux-Eglises.
3rd Corps (Wurttemberg) was on the left, advancing from Laferte-sur-Aube, south-east of Bar, north to Clairvaux Abbey and then north-west towards Mortier's main body around Fontaine.
The Allies ended up fighting two separate battles. They were most successful on their right. The Wurttembergers intended to carry out a two-pronged assault, using Stockmayer's advance guard to get around Letort's right flank while General von Jett carried out a frontal assault.
The flank attack failed, but the frontal assault, which began just after noon, was more successful, and Letort withdrew to Lignol-le-Chateau. The Wurttembergers advanced through Colombey and deployed for battle once again. The French retreated once again, bringing them close to Mortier's main force. The Wurttembergers deployed for a third time, with their left on the Aube and their right towards Voigny, but they were now facing Letort and Friant, and the fight dwindled into an artillery dual.
On the Allied left the Austrian 4th Corps (General Giulay) pushed back the French advance guards between Baroville and Bayel, and then sent Hohenlohe's division, supported by Mariassy's division, to attack Michel's brigade at Fontaine. This attack ended in failure, and the French were even able to launch a counterattack. Christiani's assault was quite successful, but Guilay committed Czollich's brigade and steadied his lines. The Austrians carried out two more attacks on Fontaine, but both were repulsed by Michel and part of the 2nd Division.
By the end of the day the French still held Bar-sur-Aube, but they had lost around 1,200 men. The Austrians lost 647 dead and wounded and 190 prisoners, the Wurttembergers 900 dead and wounded. Total allied casualites were thus just over 1,700. However the French were badly outnumbered, and overnight Mortier withdrew west to Vendeuvre-sur-Barse. From there he moved towards Troyes on the Seine