Davout frowned. ‘But, sire, if the enemy take Borisov then we will need the pontoons to make our escape across the river.’

‘They’re not necessary,’ Napoleon replied. ‘The temperature has not risen above freezing for the last five days. It is likely to get colder still, in which case the river will freeze. Hard enough for us to cross the Berezina wherever the ice is thickest.’

‘That is taking quite a risk, sire,’ Davout protested. ‘If the Borisov crossings are denied to us, and the ice cannot bear the weight, then . . .’ He shook his head.

‘That’s why we need to move as fast as we can.’ Napoleon clasped his hands together behind his back and concluded the briefing. ‘Pass the orders on to all officers. All the vehicles are to be gathered in the market place. Half the remaining draught horses are to be butchered and the meat distributed to the men. Only our soldiers, mind you. Any civilians are to look to their own devices. The army will march at dawn.’

All through the night the wagons and other vehicles were dragged out of the town and pushed tightly together. Kindling was piled beneath the axles. The injured were carried into the buildings and made as comfortable as possible on beds, mattresses and piles of straw. Those who carried them tried to block out their comrades’ desperate pleas not to be left behind. The weakest horses were led to the cattle market and slaughtered, and the army’s butchers hurriedly stripped the carcasses of meat and placed the chunks in barrels to distribute to each surviving battalion of the army. An hour before dawn, as the men were roused from their billets in readiness to begin the next march, the engineers set light to the vast jumble of vehicles and the flames licked high into the sky as the first glimmer of the coming day lightened the eastern horizon.

It was at that moment that the alarm was raised. An officer from the battalion tasked with the last watch of the night came running into the corn exchange and breathlessly announced that a column was approaching Orsha. Napoleon quickly countermanded the order to begin the march and told Roguet to have the Guard ready to repel an attack. Then, with Berthier, he followed the officer through the streets to the eastern side of the town and climbed the tower of a small church. The officer commanding the watch battalion was already in the tower, gazing towards the sunrise. He turned and saluted as his Emperor panted up the steps and joined him.

‘What is your name?’ asked Napoleon, somewhat surprised to see a captain in charge of the battalion.

‘Captain Pierre Dubois, sire.’

‘And how old are you, Dubois?’

‘Twenty-one, sire.’

‘What happened to your colonel?’