Count Langeron arrived at Bautzen with Barclay de Tolly’s detachment just four days before the battle. After the fall of Thorn they had marched at speed to the rescue of the main army. At the battle of Bautzen Langeron’s corps, under Barclay’s overall command, stood on the far right flank of the allied line, against which Napoleon’s decisive stroke – as it turned out – was to be directed, under the command of Marshal Ney. In his memoirs Langeron commented that the ground offered many advantages to its defenders but 25,000 men were needed to hold it; he had only 8,000. Eugen of Württemberg’s corps was on the allied left flank. Like Langeron, he recognized that the decision to stand at Bautzen had been taken above all for political reasons. In his view, ‘given how much we were outnumbered and given the very extended position we were holding we could not expect victory in the battle but just to inflict losses on the enemy and to conduct an orderly retreat protected by our numerous cavalry’.61
Fighting the leading general of the day at a two-to-one disadvantage, the danger was that they would be routed. Even another Friedland, let alone an Austerlitz, would probably have destroyed this allied coalition, as had happened to so many before it. A victory equal to Friedland was actually within Napoleon’s grasp on 21 May and would probably have occurred but for the mistakes of Marshal Ney.
Napoleon’s plan was simple and potentially devastating. On 20 May his limited attacks and feints would pin the allied main body along the whole defensive line which ran from the foothills of the Bohemian mountains on their left to the Kreckwitz heights on their right. These attacks would continue on 21 May. Given French numbers, it was easy to make these attacks very convincing and even to force the allies to commit part of their reserve to stop them. But the crucial stroke would be made on 21 May by Ney and Lauriston’s corps on Barclay’s position on the far right of the allied position near Gleina. In overwhelmingly superior numbers they would drive through Barclay and into the allied rear, cutting across the only roads which would allow the allies to make an orderly retreat eastwards to Reichenbach and Görlitz, and threatening to push the enemy in disorderly rout southwards over the Austrian frontier. This plan was fully viable and was indeed helped by Alexander’s obsession that the main threat would come on his left, with Napoleon attempting to lever the allies away from the Bohemian frontier and thereby wreck the chances of coordinating operations with the Austrians. In contrast, Wittgenstein correctly understood that the main danger would come in the north. By now Alexander had lost confidence in Wittgenstein, however, and was almost acting himself as de facto commander-in-chief. Moreover, Wittgenstein did not help matters by telling the emperor that Barclay commanded 15,000 men whereas in reality he had barely half that many.62
On 20 May the battle went according to Napoleon’s plan. Fierce fighting raged down the whole allied front as far north as the Kreckwitz heights and Alexander committed part of his reserves to drive back what he saw as the French threat on his left. Meanwhile Barclay’s men were bothered by nothing more than a few skirmishers. On the next morning battle was renewed from the Bohemian foothills to Kreckwitz, but Ney and Lauriston also entered the fray.
The battle on the far right began at about nine in the morning. Barclay quickly realized that there was no hope of stopping the overwhelming numbers with which he was faced. All he could hope to do was fight a delaying action on the heights near Gleina and protect the key lines of retreat as long as possible. Langeron commented that in particular his 28th and 32nd Jaeger regiments showed both skill and heroism that morning, holding off the French until the last minute and allowing the Russian artillery to escape after inflicting heavy casualties. Barclay himself went forward among his jaegers, inspiring them by his quiet courage in extreme danger. For all the Russians’ coolness and the temporary respite won by a counter-attack by Kleist’s Prussians, the situation became increasingly desperate as Ney’s pressure built up and part of Lauriston’s corps threatened to envelop Barclay’s right flank. When the village of Preititz finally fell to the French at three in the afternoon it would have been easy for Lauriston to move forward to cut the vital allied line of retreat down the road to Weissenburg.