Marshal Davout arrived at headquarters as Napoleon was finishing his breakfast and the Emperor instantly rose to his feet and thrust his napkin aside as he smiled at his subordinate.

‘Marshal Davout, it is a pleasure to greet the victor of Auerstadt! Please, sit down and join me. Coffee? Something to eat?’

‘Thank you, sire. Coffee would be most welcome.’

Once Napoleon had ordered a clerk to bring refreshments for the marshal, he glanced over at his guest. Davout had ridden through the night, and had not slept for three days. A thick stubble encrusted his cheeks and his eyes were red-rimmed and bloodshot. He eased himself stiffly into the chair opposite the Emperor and smiled wearily. ‘May I offer my congratulations to you, sire, on your victory here at Jena?’

Napoleon laughed.‘Two triumphs in one day. Providence was surely shining on French arms yesterday.’

‘Yes, sire.’

‘So tell me, Davout. What happened? According to Murat’s scouts you should have been facing a small corps protecting the enemy flank.’

‘Even Marshal Murat makes mistakes from time to time, sire,’ Davout replied wryly and they both smiled before he collected his thoughts and continued. ‘I crossed the Saale ten miles along the river from here, in accordance with your orders, sire. I deemed it best to march on Apolda as quickly as possible in order to block any Prussian retreat from Jena. So I advanced with Gudin’s division and ordered the others to follow as swiftly as possible. We were over the Saale by dawn, and there was a dense fog covering the landscape.You must have had the same here.’

Napoleon nodded.

‘So we continued to advance and our cavalry patrols ran into enemy scouts. The prisoners told us that they belonged to Brunswick’s army. I doubted their word, as you can imagine, and continued advancing as far as the village of Hassenhausen, when the fog began to lift and we saw for the first time the Prussian army spread out before us. I sent word to you at once, sire, and also to Marshal Bernadotte to march his corps to support mine.There was very little time to do anything else before the Prussians attacked. Gudin’s men formed squares and held them off and they fell back.There was a delay while they prepared to attack again, but by now Friant’s division had reached the field and I could see that Brunswick would attempt to get round our right flank, so I sent Friant to the right and shifted Gudin’s centre in the same direction.’

‘What of your other flank?’ Napoleon asked sharply. ‘You can’t have left that unguarded, surely?’

‘No, sire. It was covered by one regiment.’

‘One regiment?’