Masséna’s formations pulled back, apart from one division left behind to defend Aderklaa. As soon as they were a safe distance from the enemy, the French soldiers turned about and began to quick-march across the plain towards Essling. The race was on, Napoleon realised, his stomach knotted by anxiety. If the enemy captured Essling and moved swiftly enough, they would take the bridges over the Danube. He could see Masséna riding up and down the columns of blue-coated infantry, urging them on. Despite having had little sleep for nearly three days the men stepped out in a lively fashion, kicking up a thin haze of dust from the dry ground.

A series of sharp bugle notes pierced the morning air and Napoleon turned to see the first of Bessières’s charges ripple forward towards the Austrian centre. A line of cuirassiers trotted across the plain, breastplates and helmets shimmering as their crests swished from side to side. Half a mile in front of them the nearest units of Austrian infantry began to form squares while the gun crews trained their cannon on the new threat.

‘A brave sight,’ Napoleon commented. As the horsemen closed on the Austrians and increased their pace to a gentle canter, there seemed to be a pause in the fighting on either side of the battlefield as the two armies watched the wave of men and horses thundering over the flattened grass and crops of the plain. The brief spell was broken as the first of the enemy batteries opened fire, scouring the leading ranks of one of the cuirassier regiments. Scores of men and horses went tumbling over as if they had been tripped, and the succeeding lines had to swerve round them like eddies in a stream. More guns joined in, decimating the ranks of the French heavy cavalry. The bugles sounded again, ordering the charge, and the riders dug their spurs in, extended their sword arms and let out an exuberant cheer that could be clearly heard by Napoleon and his staff officers as they watched.

The Austrian gunners turned away from their weapons and ran for the shelter of the nearest squares, throwing themselves flat at the feet of the kneeling front rank as the latter’s muskets came up, ready to fire into the approaching cavalry. The face of the closest Austrian square abruptly disappeared behind a line of gunpowder smoke and several more of the cuirassiers were cut down. The rest plunged on, riding into the smoke.

The squares of the enemy’s front line held firm, and the French horsemen were forced to flow round them, fired on as they galloped past. Some tried to lean from the saddles and slash at the Austrians with their swords. Others, more cool-headed, sheathed their blades and drew out their pistols, firing back at point-blank range. All the time, the Frenchmen were steadily cut down and the wounded trickled back across the body-strewn fields towards the French lines. The second wave of horsemen opened ranks to let them pass through, and then moved forward to add their weight to the survivors of the first charge.