Berthier shut his eyes and shook his head gently before he responded. ‘But, sire, you will suffer attrition with each battle, and the odds of winning become less favourable. Besides, many of the regiments in the army are under strength. To stand any chance of defending France you must find far more men.’

‘Which I am in the process of doing,’ Napoleon replied defiantly. ‘Once King Ferdinand ratifies the peace treaty between Spain and France then tens of thousands more men will be available. And more, as soon as Murat sends reinforcements from Naples. Meanwhile, there are two divisions forming at Lyon. They will march north to reinforce me the moment I call on them.’

‘They are merely boys and invalids, sire. Many of them have still not been issued full uniforms, or muskets. They cannot be considered as front line units.’

‘We are all in the front line, Berthier. Every soul in France has been in the front line from the moment the enemy crossed our border. But rest assured, I will only fight delaying actions until the moment I can attack each of their armies at an advantage.’

‘Even if that means retreating as far as Paris, sire?’

‘Even that,’ Napoleon conceded.

Berthier slumped back in his chair. He sighed. ‘Then we must make ready the capital’s defences, sire. The people need to be prepared for the worst. We must lay in rations to feed the population and the garrison, mount every spare cannon on the walls and in the forts.’

‘No.’ Napoleon shook his head.‘If the people think that Paris will be attacked then it will only result in panic and strengthen the hand of those traitors who seek to bring France low. There will be no attempt to prepare any defences. As far as the people are concerned, they are safe from the enemy. Is that perfectly clear?’

‘Yes, sire,’ Berthier replied patiently. ‘But if, for the sake of argument, the enemy are able to advance far enough to attack Paris, what then?’

‘Then there will be no attempt to abandon the city. The garrison and the people will resist the invader to the last breath, and if necessary we must bury ourselves under its ruins.’

There was silence in the room as Berthier stared at the Emperor, then exchanged brief glances with the others. He cleared his throat. ‘Sire, that is not a strategy. There is no honour, or purpose, in a ruler dragging a civilisation down to destruction. After what happened to Moscow we can be sure that the Tsar would happily destroy Paris in revenge. We cannot risk the capital, or its people, in this way. Either you give the order to prepare Paris for a siege, or, if you decide that it cannot be defended, it must be declared an open city.’