2000 1st September 1813
Wellington has joined 2nd allied corps at Castillo the previous day.
Graham reported that 1st Spanish corps had lost heavy battle casualties, and would not be ready to take the field for at least 24 hours. 2nd British division had only suffered light casualties, and were fully operational. Both divisions were fully resupplied.
The allied corps commanders had been lax in their daily reports to Wellington, and he was unaware of the current operational readiness of 1st and 3rd corps. The previous evening he had written to both commanders to confirm their exact strength and supply position.
Throughout 31st August 1813 there had been the sound of heavy fighting at Pancorbo. During the night unofficial reports had arrived of a complete disaster. One even suggested that all of 1st corps had surrendered to the French.
He had expected 3rd corps to attack Burgos at first light, but as the day progressed there were no sounds of battle, nor any reports to an allied attack.
Just after lunch Wellington one of General Hills ADC arrived with confirmation that 1st allied corps had indeed lost the battle at Pancorbo. 1st British division had broken and run, but been forced to surrender when cut off by the much stronger French cavalry. 2nd Spanish division had been surrounded at Pancorbo and forced to surrender.
With the loss of one third of his army it was clear to Wellington that he had lost the campaign and must immediately retreat if he was to save the rest.
Messengers were sent to 2nd and 3rd corps to abandon their heavy baggage and ammunition and immediately retreat to Valladolid.
The Burgos campaign was over.