Josephine turned and swatted him on the shoulder with her fan. ‘What is wrong with my darling dog?’

Napoleon glanced at the pug, which promptly bared its teeth at him. ‘Let’s just say his bite is worse than his bark.’

The time that Napoleon could spare for Josephine was as precious to him as any treasure, especially since the Austrians were intent on relieving the fortress at Mantua. Towards the end of July a new offensive was launched from the Tyrol under an old veteran, General Wurmser. Napoleon was roused from the bed he shared with Josephine in the early hours, and for several days he hardly left his saddle as the French army was driven back by the enemy advancing in three columns. For his men, so used to advancing, being forced on to the defensive was an unfamiliar and dispiriting experience. So dangerous was the situation that Napoleon was forced to summon Serurier from Mantua, with orders to spike all the siege guns that had just been laboriously positioned to bombard the fortress. With all his men concentrated into a single force, Napoleon fell on each enemy column in turn and defeated them all. The routes down which the Austrians retreated were choked with bodies, abandoned cannon and wagons. Muskets and other equipment had been cast aside as they fled, and all that remained were the stragglers and the wounded, sitting amid the wreckage of their proud army as they waited to be taken prisoner.

Even so, before falling back with his battered army Wurmser had managed to reinforce and resupply Mantua and now, to Napoleon’s intense frustration, the fortress would be able to hold out for several more months. Serurier’s men, who returned to the siege, rapidly began to succumb to the unhealthy conditions in the surrounding marshes and by August over fifteen thousand of his men were on the sick list. Every large building in the country around Mantua was packed with suffering soldiers, racked by fever and hunger, while outside the lines of the graves lengthened day by day. There was no question of an assault on the fortress. The best that could be done was to blockade the garrison and hope to starve them out.

‘It’s impossible!’ he raged at Berthier one evening in August, after reading the latest dispatches from his masters in Paris. ‘They might have abandoned that absurd plan to split the army, but how can we defeat Austria when the Directory starves us of reinforcements? Now it seems they want us to launch an attack on Naples. With what?’ He threw the letter aside with a look of bitter contempt. ‘I have barely enough men to hold the line against Wurmser. Do they think I can conjure soldiers out of thin air?’

Berthier waited a moment for his general to calm down, and then spoke quietly. ‘You must write to them, sir.’

‘Another letter?’ Napoelon shook his head. ‘What use would it serve?’