The Prussians continued to take the punishment for the next two hours. Once Lannes’s skirmishers realised that the enemy were not going to move, they crept forward and added their fire from the houses of the village, and from behind the low walls that surrounded the villagers’ vegetable gardens. In return the Prussians fired volleys by company, reloading and firing again with little hope of causing any harm to the sheltered Frenchmen. The worst casualties suffered by Napoleon’s men came from a handful of lucky shots from Prussian howitzers that landed amongst the artillery caissons of the French batteries and blew up one of the powder wagons, scattering fragments of the vehicle, its horses and their handlers across the surrounding ground.

While the duel on the right flank continued, more French troops were arriving on the battlefield and taking position as they waited for the order to attack. As the last of Murat’s cavalry formed up behind the centre of the French line Napoleon glanced down at his watch and saw that it was half an hour after noon. He glanced round at Berthier.

‘Send an order to all divisions. The army is to execute a general attack at one o’clock.’

‘Yes, sire. All divisions,’ Berthier repeated, and then gestured to the neat ranks of the Imperial Guard standing ready behind the Emperor’s command post. The men in the front rank had eager and excited expressions and there was no mistaking their desire to take part in the attack. ‘Does that include the Guard, sire?’

‘No.’ Napoleon shook his head emphatically. He had nearly suffered a defeat at Marengo for want of adequate reserves. In any case, he reasoned with himself, this battle was as good as won and there was no need to commit the veterans of the Guard to the fight. He glanced over at the heavily moustached faces of the nearest men of his elite corps and could see their disappointment at his decision.‘The campaign is not yet over,’ he added loudly enough for them to hear. ‘The grumblers will have the chance to win their share of glory another day.’

On the hour the entire French line began to advance and once more the plateau was engulfed in acrid powder smoke, and the air resounded with the ear-splitting roar of artillery and the crackle of musket fire. For a while the Prussian line held and the men of the Imperial Guard began to mutter bitterly about their inactivity. Napoleon kept his back to the men and resolutely refused to acknowledge their discontent, until a voice cried out, ‘The Guard must advance! For pity’s sake, sire, do not shame us!’

Napoleon turned abruptly and stabbed a finger towards the nearest men. ‘Who said that?’

There was a sullen silence, and then one of the younger soldiers stepped a pace forward and presented his musket. ‘Sire!’