‘It would have been mine in the long run,’ Ferdinand countered. ‘Besides, if I had waited much longer the people would have risen up and taken the crown from him, and then we would have had a full-blown revolution on our hands.And we know where that leads. I would spare my people such terror, and tyranny.’

Napoleon ignored the gibe. ‘It is true that you might have acted for the good of the people. It is equally true that you might have acted out of naked ambition and a hunger for power.That is for people to decide for themselves. Either way, you cannot command the respect of other nations while your assumption of the crown is shrouded in confusion and suspicion over its legality.’

Ferdinand shrugged helplessly. ‘So what am I to do?’

‘You must return the crown to your father and apologise, in writing, for what you have done.’

‘No.That is not possible.’

Napoleon smiled. ‘You have little choice, your highness. If you are permitted to seize power in the manner that you have, you will have set a precedent. What if every royal prince thought to emulate you? No ruler would be able to sleep. Nations would be paralysed by fear, Spain most of all. I tell you, Ferdinand, you would forever be jumping at shadows, until the day when the conspirators came for you. And on that day there will be no Marshal Murat and his soldiers to save you from the wrath of the mob.’

Ferdinand pondered for a moment and then opened his hands. ‘So what am I to do?’

‘You must return the crown to the King and then wait your proper time to inherit the throne. It will come soon enough. Charles is old and weak. When he is no more, then you will have your crown, legally and without recrimination from any royal court in Europe.’

‘I suppose so.’

‘There is one other thing,’ Napoleon said evenly.‘You must apologise for your treatment of the King.’

‘Apologise?’ Ferdinand’s eyes widened. ‘Never.’

‘You must. Your recent actions will not be forgotten. Would you want people to still regard you with suspicion and misgiving when the time comes for you to assume the crown? There must be some act of contrition first.You must issue a public apology and return the crown.’

‘What if I refuse to do either?’

Napoleon stared at him a moment before continuing in a low, menacing voice. ‘You cannot refuse. I will not permit it. I could easily place you under arrest and keep you here until you renounce the throne. I might even try you for treason, on your father’s behalf, and have you shot.’

Ferdinand’s jaw dropped in astonishment for a moment before he recovered and shook his head. ‘You cannot threaten me.’

‘No? Why not? You threatened your father into signing a document. Why should I not do the same to you?’