‘Sire,’ Berthier responded with a warning glance, and then looked round at the other officers in the barn. Some were hunched over campaign tables, busy writing orders, while others collated the latest strength returns, a task that daily revealed the increasing peril of the Grand Army as the number of men in each corps dwindled. Satisfied that he would not be overheard, Berthier continued. ‘You must remain with the army for as long as possible. While you are with us there is still some hope for the men. They trust you, sire. They know that you will lead them out of this frozen wasteland. But if you leave . . . if you abandon them, then whatever is left of their fighting spirit will die. The army will dissolve. We have to save as many of them as possible, else there will be nothing to stand between our empire and the forces of Russia when the next campaign season begins.’

Napoleon frowned at his chief of staff. ‘You exaggerate the danger, as ever, Berthier. What makes you think these conditions affect the enemy any less than us, eh? The Russians are still men. They feel the cold. They grow hungry as they outmarch their supply lines. I dare say that, even now, Kutusov is sitting in his headquarters listening to a doom-mongering subordinate of his own. The Russians will be in no better condition to continue the war than we are when the spring comes.’

‘You are wrong, sire,’ said Berthier. ‘The Russians are living within their supply lines. Their men have food when they need it, and are not obliged to try to carry it with them every step of the way.’

‘Nor will we be when we reach Smolensk!’ Napoleon snapped back. ‘There are rations enough there for all the men. The city has strong defences. The army could winter there while I return to Paris, and when the spring comes we will be within striking range of St Petersburg. If the loss of Moscow does not move the Tsar to seek peace, then perhaps if we take his new capital he will begin to see reason. If that does not work we shall take his cities one by one, and burn them, until he comes to terms.’

Berthier shook his head. ‘I am no longer sure that the loss of all his cities would weaken his will to resist. In any case, if the Grand Army, or what’s left of it, remains in Smolensk then it runs the risk of being trapped there during the depths of winter. And all the time the enemy will be drawing on his reserves to increase the size of the armies gathering against us. Come spring they will be ready to close the trap around Smolensk and compel the army to surrender, or perish. There would be no army for you to return to, sire.’