To the right, Oudinot and Davout led their men across and drove the enemy back as they fanned out across the plain and formed their corps up on Masséna’s right flank. By the early hours of the morning half of the Grand Army was already over the Danube. Napoleon and his staff crossed the river and set up headquarters in the hamlet of Uferhaus, where the Emperor’s bodyguard unceremoniously turfed out the owner of a small estate and surrounded the walls with pickets. Inside Napoleon sat at a hastily arranged map table and took a bowl of soup as Berthier eagerly read over the reports sent back from each of the three corps which had already crossed the river.

‘No reports of any serious opposition, sire. The Austrians seem to be retreating right across our front.’ Berthier sifted through a few more sheets of paper before he looked up again. ‘Casualties are minimal.’

‘Good. And what of the bridges? Are they still in one piece?’

‘As far as I know, sir. At least, there have been no reports to the contrary.’

Napoleon stared at his subordinate for a moment, wondering if he could trust his junior officers to keep him fully informed of the army’s progress across the river. After the debacle of the last attempt to force a crossing of the Danube, Napoleon was determined to ensure that the army’s lines of communication were unhindered. He pushed the bowl to one side. ‘Berthier, send an officer to the river bank. I want to know the instant anything happens that might frustrate our plans, in any way. Is that clear?’

‘Yes, sire.’

Napoleon gazed at the map, deep in concentration. By dawn three army corps and the Imperial Guard would be drawn up in a line facing north across a six-mile front from the bank of the Danube across the plain to the east. A hundred thousand men. Opposed to them would be a hundred and fifty thousand Austrians. Napoleon was confident that his men could hold their line, even though outnumbered, until the last formations of the Grand Army crossed the Danube and swelled the total to over a hundred and eighty thousand men. If Archduke Charles retreated, then the Grand Army would be obliged to pursue him, all the time stretching their lines of communication, and being forced to leave behind men tasked with guarding vital supply routes.

Very well, then, Napoleon resolved, the enemy must not be given any chance to break contact. At first light, the first three corps must be launched against the Austrians, forcing them to stand and fight.