‘What is Ney doing?’ Napoleon fumed.‘What is that fool up to? He has no orders to advance yet. He can’t attack by himself.’

Behind the Emperor the staff officers and messengers stood silently and watched helplessly as Ney’s men closed on the enemy and began to deploy as the first of the Prussian guns ahead of them opened fire, orange flames stabbing through puffs of smoke that looked like tiny flowers at a distance. Through Napoleon’s telescope the effect on the delicate-looking lines of French soldiers was all too real, however, as round shot swept away whole files of men at a time. With painstaking steadiness Ney’s men completed the manoeuvre and advanced towards the enemy line. The bright colours of each battalion’s standard led the way and the waving swords of the officers glittered like far-off stars as they caught the morning sun. The enemy cannon continued to cut scores of men down as the French advanced and then, as they closed up on the Prussian line, they halted and made ready to fire.

There was a pause, then a final volley flashed out from the Prussian guns.An instant later, Ney’s men replied. Scores of men fell on each side, and then Ney’s infantry charged through the musket smoke and made for the enemy artillery positions.There was no time for the Prussians to reload and they fled from their guns, abandoning them to the French.

Berthier clapped his hands. ‘They’ve done it! They have the guns!’

‘Yes.’ Napoleon nodded. ‘And at what cost? The fool has advanced too far, and has no support. Look there, now Ney will really have his battle.’

Napoleon pointed out the dense mass of enemy cavalry already edging forward from the rear of the Prussian lines. They had been moving forward to counter Lannes’s attack, but the Prussian general had seen his chance to crush Ney’s isolated formation and the long lines of mounted men closed in on the French infantry. Ney did the only thing that he could under the circumstances, and Napoleon watched the distant infantry hurriedly form squares and prepare to receive the charge of the enemy cavalry.The Emperor had little doubt that Ney and his men would hold off the Prussian horsemen, but they were not the real danger.While Ney’s corps held off the cavalry the Prussians would bring forward more guns and infantry to blast the static French formations to pieces.They could not possibly endure such punishment for long, and the squares would break down. At that point they would be entirely at the mercy of the Prussians.

Napoleon frowned bitterly.‘Ney has forced my hand.We have to save that Gascon fool and his men.’ Napoleon turned away from the scene, his mind swiftly conceiving the necessary orders. ‘We need cavalry. Where is Murat?’