Napoleon turned back to observe the battlefield, but the new flurry of snow blotted out all sight of any detail beyond a hundred paces. Once again the sounds of cannon and musket were muffled and it was impossible to judge the distance, or even the direction. Napoleon gripped the parapet of the church tower as he stared anxiously into the swirling white specks and strained his ears. Down below in the streets of Eylau he could see the occasional dark shapes of men fleeing from the Russians. Survivors of Augereau’s corps, Napoleon surmised.Thanks to their commander, there was now nothing between Napoleon’s command position and the enemy.

A burning sensation in his fingers made Napoleon gaze down and he realised that his hands were losing feeling in the biting cold. He cupped them against his mouth and blew hard for a moment before rubbing them vigorously until the circulation returned, painfully. He pulled his gloves out of his coat pocket and put them on.The conditions under which the battle was being fought were truly appalling, he thought. He had hoped to pin the Russians while Ney and Davout crashed into their flanks to inflict a stunning defeat on the Tsar’s army. Instead, there was no sign of Ney and Davout’s men were arriving piecemeal, and the rest of the French line was in danger of collapsing. With a sudden frightening clarity, Napoleon saw that this day might well mark the loss of the Grand Army and with it all his dreams for dominion over Europe.

It was Berthier who saw the danger first as he leaned forward over the parapet and stared into the blizzard. ‘Sire, I think the enemy are sending infantry forward.’

‘What?’

‘There, look!’ Berthier thrust his arm out and pointed over the roofs of Eylau to the edge of the town. Sure enough a dark smudge was just discernible as it emerged from the gloom. A fluke in the wind provided an instant when the sky was clear and Napoleon could see the approaching Russian column plainly. No more than two hundred paces away, marching swiftly through the snow as the officers and sergeants urged their men on, scenting the chance of victory if only they could shatter the French centre before it could be stabilised.

Napoleon turned and ran across to the far side of the church tower and stared towards the French reserves, but the lines of the Imperial Guard had still not moved forward; Berthier’s order could not have reached them yet.The Russians would be upon the men of the imperial headquarters before help could arrive. Napoleon whipped round towards his staff officers.