‘How far have the enemy advanced?’

‘When I left General Boudet the Austrians were approaching Essling, sire.’

‘Essling!’ Berthier turned to Napoleon with a look of horror. Glancing round at his staff officers he saw that the news had stunned them. There was fear in some expressions too. He had to steady their nerves. He must set the example, or all was lost. Forcing a calm expression on to his face, Napoleon addressed Berthier. ‘We have two options. We ignore this attack and continue with the plan, and hope that Davout successfully crushes the enemy’s left flank. Or we send Masséna to block their advance, hold the bridges and then force them back.’

‘But Masséna is already engaged, sire. Besides, even if he could break contact, he would have to march across the face of the Austrians on our left. If they can bring their guns to bear then Masséna’s men will be mauled.’

‘That’s possible,’ Napoleon conceded. ‘My conviction is that the Austrians will not be able to bring their guns into action fast enough to do much harm to Masséna. Everything will depend on our speed. Firstly we must extricate Masséna and prevent the enemy from trying to maintain contact. The reserve cavalry are to charge the enemy forming to the west of Aderklaa. They must pin them in place long enough for Masséna to reach Essling and form his line there.’

Berthier nodded.

‘If Bessières fails, then our centre cannot possibly be held. The Grand Army will be cut in two. Make sure Bessières understands the danger we are in.’

‘Yes, sire.’

The situation was critical, Napoleon realised. As at Eylau, his battle line was in danger of shattering under enemy pressure. If the cavalry could relieve the strain on the rest of the army there was some chance that the line could re-form and hold off the enemy. While he watched the cavalry come forward and form lines ready to charge the enemy centre, Napoleon saw movement behind Masséna’s corps as a division from Eugène’s corps and some batteries of artillery crossed the rear of the formation and formed a line facing the enemy columns advancing along the bank of the Danube. With a nod of approval and relief, Napoleon realised that his stepson had acted on his own initiative to attack the enemy’s flank. The crews hurriedly unlimbered their cannon and loaded case shot. Within minutes the first of them was in action, belching flame and smoke as the gun carriage leaped back on the recoil. More guns joined in and soon began to tear holes in the Austrian columns passing by their front. As the enemy soldiers were scythed down, each battalion had to slow to step over the bodies and re-form their ranks, buying vital time for Masséna.