The battle of Wartenburg (3 October 1813) was a key battle in the campaign that led to Leipzig, and saw Blücher's Army of Silesia gain a firm foothold on the left bank of the Elbe, putting all three of the main Allied armies on the same side of the river.
On 24 September the French began a retreat back to the Elbe, abandoning Eastern Saxony. Marshal Ney, with Bertrand's IV Corps and Reynier's VII Corps (or at least the survivors of the defeat at Dennewitz), was given the task of defending the left bank of the Elbe from Torgau to Wittenberg, a distance of over 25 miles.
He faced two threats. Bernadotte's Army of the North had slowed moved down to the Elbe after winning at Dennewitz, and from the middle of September onwards kept building and then removing bridges over the Elbe. Around 25 September Bülow's Prussians corps from this army built two bridges opposite Wartenburg, towards the northern end of Ney's line.
The second threat came from Blücher's Army of Silesia, which had been campaigning in Silesia and Eastern Saxony. The decision had now been made to send this army north-west to join with Bernadotte, and on 24 September Blücher began his march, moving north-west down the Black Elster valley towards the Elbe east of Wartenburg.
On 1 October Ney ordered Bertrand to move to Wartenberg to prevent Bülow from crossing the Elbe there, a move that would have cut Ney's line in half. Bertrand arrived at Wartenburg on 2 October, only to find that Bülow's corps had been replaced by Blïcher's army. Bertrand was thus outnumberd 13,000 to 60,000 (although on the day Blücher committed less than 13,000 men to the attack).
Bertrand did have one advantage. The Allies had chosen to cross at Wartenberg because the Elbe swept around in a big bend east of Wartenberg, forming a peninsular with the river on three sides and the village on the fourth (western) side. This allowed them to support the crossing with artillery from three sides. However the area between the river at Wartenberg was extremely difficult terrain - marshy and full of areas that flooded when the Elbe was running high. The village itself was protected by an embankment built to serve as a flood barrier. If the river had been higher, then it would have been almost impossible to take Wartenburg in the face of determined opposition.
The French line ran from Wartenburg, across the neck of the peninsula, south-east to the village of Bleddin. Franguemont's Wurtemberg troops held Bleddin. Morand's division was in Wartenburg and Fontanelli's division was in the reserve.
The first Prussian troops, three battalions from Yorck's corps under Prince Charles of Mecklenburg, crossed the two bridges at around 7am on the morning of 3 October. Once they were across the river it quickly became clear to the Prince that he couldn't make a frontal assault on Wartenburg. Instead he would have to turn left, and advance along a narrow strip of dry land between the Elbe and one of the flooded areas to attack Bleddin. Yorck confirmed this after he crossed the bridges, and the Prince began a slow movement south.
Prince Charles was followed across the Elbe by Steinmetz's brigade. This was used for a frontal assault on Wartenburg, but as expected was unable to get past the embankment east of the village. Horn's brigade was moved into the gap between Steinmetz and Prince Charles, but was also unable to make any progress, at least at first.
At about 1pm Prince Charles began his attack on Bleddin. Franquemont was forced to retreat north-west towards Wartenburg. This movement was halted by Horn, who managed to block his route. Franquemont was forced to pull back to his right, away from the battle, losing most of his artillery and only escaping with 900 infantry and 200 cavalry. By 2pm the Prussians had captured Bleddin.
By this point Blücher had arrived on the battlefield. Steinmetz was still stuck at the embankment. Horn was attempting to attack Wartenburg from the south-east, but without success. Blücher ordered Prince Charles to attack Wartenburg from the south-west, and although he could only commit 700 men and 9 guns to the attack, by 3.30 Morand had been forced to retreat west from the village.
The French retreated west down the Elbe, with Morand on the left and Fontanelli on the right. They suffered some losses to artillery firing across the Elbe, and Mecklenberg's cavalry took some prisoners in an attack on Fontanelli's column, but the Allies were unable to mount a serious pursuit.
The Prussians lost 67 officers and 1,548 men during this battle. The French lost fewer men killed or wounded but another 1,000 prisoners.
On 4 October the rest of Blücher's army crossed the river. On the same day Bernadotte crossed at Rosslau (24 miles to the west) and Barby, further downstream. Ney now had Allied troops to his west and to his east, and was forced to retreat south towards Delitzsch, north of Leipzig. All three Allied armies were now on the same bank of the Elbe, and although Napoleon had a brief chance to catch Blücher and Bernadotte, he would miss it and end up having to fight all three at Leipzig.