The combat of Bischofswerda (22 September 1813) was a minor French success that saw Napoleon push Blücher back from a threatening position between Bautzen and Dresden.
A key feature of the autumn campaign of 1813 was the inability of Marshal Macdonald and his Army of the Bobr to stand up to Blücher when Napoleon was absent. The worst setback came at the Katzbach (26 August), where Macdonald suffered a heavy defeat, but the same pattern was repeated several times. The last of them came in mid-late September 1813, just before Napoleon decided to abandon all of his positions east of the Elbe. While Napoleon waited at Dresden for an Allied mistake, Blücher pushed Macdonald back towards the city. On 19 September Macdonald reported that his flanking forces had been pushed back to Radeberg, only ten miles to the east. Blücher's main forces were still much further east, around Bautzen, but even so Napoleon was forced to sent two divisions of the Young Guard, under Mortier, to support Macdonald.
At 2am on 22 September Napoleon wrote to Macdonald, ordering him to send out a reconnaissance in force to try and find Blücher's main force. Soon afterwards Napoleon decided to join Macdonald in person, and later that day he reached Harthau, six miles to the east of Radeberg.
Under Napoleon's command II Corps and XI Corps pushed back Blücher's advanced guards. They then captured Bischofswerda, four miles to the east of Harthau. Girard, with the advance guard, advanced to the Spree, and Lauriston entered Neustadt.
On the following day Blücher withdrew to Förstgen, described as being 'short of Bautzen' by Petre (Napoleon's Last Campaign in Germany), although it isn't clear on which side (presumably to the west). Napoleon had now realised that Blücher's retreats were a deliberate move to avoid any battle against him, and returned to Harthau.
In the aftermath of this last sortie east of the Elbe, Napoleon decided to withdraw to the left bank of the river. The Elbe would help guard against any surprise moves by Blücher in the east or Bernadotte in the north, and Napoleon might be given a chance to attack Schwarzenberg's army. Instead this move began the campaign that ended with the massive battle of Leipzig, the battle that ended any chance of Napoleon hanging on to his position in Germany.