‘For what we are about to receive,’ Berthier muttered as he strained his eyes to observe the leading elements of the division closing on the enemy defences.

The Austrians held their fire until the French skirmishers had almost reached the wide ditch in front of the town’s walls. Then hundreds of tiny puffs of smoke pricked out along the walls as bright tongues of flame stabbed from the guns mounted on the towers and redoubts. Napoleon raised his telescope and saw that scores of the skirmishers had been cut down, and behind them the leading ranks of Lannes’s columns reeled as they were subjected to a storm of lead musket balls and the iron shot of the guns. The officers raised their swords high, some placing their hats over the points to make them more visible, and urged their men on. The soldiers surged over the lip of the ditch and were lost to view for a moment before they reappeared, scrambling up the far slope and running on towards the wall. Above them, the battlements of the town were lined with the white uniforms of the Austrians, barely visible through the drifting banks of smoke that hung in the air like a tattered shroud. All the while, the attackers were being whittled down as they tried to reach the wall.

Then, quite abruptly, the forward impetus died as the soldiers went to ground, huddling behind whatever cover they could find as they desperately exchanged shots with the enemy. Still more men entered the ditch, crowding those on the far slope who refused to advance any further. The dense mass of humanity presented an irresistible target to the enemy, who swept the ditch with case shot while grenades were lobbed down from the walls. They detonated with bright flashes, shooting shards of jagged iron in every direction, mutilating the men of Marshal Lannes’s first wave.

‘Damn.’ Napoleon frowned irritably. ‘Damn them. Why do they sit there, and die in that ditch? If they want to live, then they must go forward.’

His frustration grew as the slaughter continued. At length the inevitable happened as the men of the first wave slowly began to give ground, and then the pace increased as the urge to retreat spread through the soldiers like an invisible wave rippling out through their ranks. Within minutes the last of the survivors sheltering in the ditch was hurrying away from the town, leaving the dead and wounded sprawled and heaped before the wall. As the men streamed back the Austrians continued to fire after them until the French were out of musket range, and then only the cannon continued, firing several more rounds of case shot before they too fell silent.