After holding his main defensive positions in stiff fighting, Mortier withdrew his elite troops during the night and retreated to Troyes.

King Frederick William III of Prussia was ready to go along with the czar and his countrymen were eager to avenge years of French occupation and humiliation.

Francis and his minister Klemens von Metternich feared Russia and Prussia might gain too much power if France were crushed.

[3] The Coalition planned to send the main Army of Bohemia under Prince Karl Philipp of Schwarzenberg to invade France via Switzerland and march to Langres.

[5] At first Napoleon hoped that the invading Allied armies numbered only 80,000 men but they fielded 200,000 troops, to which the French emperor could only oppose 70,000 soldiers.

[8] Because of the French generals' weak forces, the Coalition armies' advance from the frontiers to the Marne River was hardly opposed at all.

[9] Langres was held by Marshal Édouard Mortier, duc de Trévise with units of the Imperial Guard.

[10] On the evening of 12 January 1814, at Chatenay-Vaudin, 300 guardsmen surprised a strong Austrian patrol from Gyulai's III Corps, capturing 27 soldiers and killing the rest.

The Germans rushed across and nearly captured the village but were routed by a Guard Foot Grenadier bayonet attack that inflicted numerous casualties and took 60 prisoners.

By nature a cautious general, Schwarzenberg was jittery about his lengthening supply lines stretching back to the Rhine, partly explaining the Army of Bohemia's slow 5 mi (8.0 km) per day advance.

[14] Mortier reached Bar-sur-Aube on 20 January and that afternoon his force was joined by the 2nd Old Guard Division led by Charles-Joseph Christiani and the 113th Line Infantry Regiment under Louis Auguste Victor de Bourmont.

Mortier complained in a letter to Napoleon's Chief of staff Marshal Louis-Alexandre Berthier, that Christiani's division had fewer than 3,000 men.

During the next few days major units of the Army of Bohemia remained inert though both the III and IV Corps gathered intelligence of Mortier's positions from patrols.

Alexander urged Schwarzenberg to advance and when the Austrian made weak excuses, the czar accused him of sabotaging the campaign.

To placate Alexander, Schwarzenberg agreed to a plan of attack that Gyulai and the Crown Prince submitted to his headquarters.

He found that several thousand Don Cossacks under Matvei Platov lurked at Doulevant-le-Château only 15 miles (24 km) to the north-east.

The remaining six field pieces were with Louis-Michel Letort de Lorville's four battalions and four squadrons at Colombey-les-Deux-Églises to the east of Bar.

[19] According to their plan, Gyulai would assault Bar-sur-Aube at the same time that the Crown Prince attacked Colombey-les-Deux-Églises and Platov turned Mortier's left flank.

To trap Letort's force, Ludwig von Stockmayer with three light infantry battalions, four cavalry squadrons and one horse artillery battery set out from Juzennecourt at 9:00 am and marched west to Montheries.

At that village, they planned to turn north through the Dhuits Forest and come into the main highway west of Colombey-les-Deux-Églises while other forces would attack Letort frontally.

The Crown Prince decided not to engage the French Guard infantry and withdrew his troops to Lignol, until Gyulai's advance showed some progress and conducted an artillery duel until dark.

[21] Gyulai tried to break off the combat but found his own troops under attack by the French in a prolonged struggle for the Aube crossings.

The Austrian general became angry that his Württemberger allies remained in place while his corps bore the brunt of the combat; evening ended the fighting.

[23] One authority stated that the Allies sustained 1,400 casualties out of 12,500 men but listed only Austrian III Corps units.

[25] At 11:00 pm, Mortier notified Napoleon of his plans to retreat to Vendeuvre-sur-Barse and immediately sent orders for his troops to begin evacuating Bar-sur-Aube.

[27][24] Historian David G. Chandler stated that Mortier suffered a "narrow defeat"[28][1] while Francis Loraine Petre reported that the action was "indecisive".

The second brigade of General-major Joseph Friedrich von der Trenck consisted of six squadrons of the Rosenberg Dragoon Regiment and another St. George Grenz battalion.

General-major Franz Splényi de Miháldy's brigade had two battalions each of Infantry Regiments Mariassy Nr.

[31] On 1 January 1814, Field Marshal the Crown Prince of Württemberg's IV Corps comprised an infantry division commanded by Lieutenant General Christian Johann Gottgetreu von Koch and a cavalry division under Lieutenant General Prince Adam von Württemberg, a total of 11,569 troops.

General-major Christoph Friedrich David Döring's 2nd Brigade included two battalions each of Infantry Regiments Duke Wilhelm Nr.