Napoleon pressed his lips together briefly. He was pricked by guilt, and then a wave of self-justification swept the sentiment away. Had he not given his brother every privilege and opportunity that he now enjoyed? Had he not placed Joseph on the throne himself? Had he not given him ample military power to enforce his rule and bring peace to the turbulent Spaniards? What had Joseph given him in return? Incompetence and failure.

‘I am not obliged to refer my decisions to anyone. If I choose to seek advice then I will. In any case, I need to secure peace in Spain as swiftly as possible. So far you, and my marshals, have failed me. Which is all the more galling bearing in mind that I have provided you with such rich rewards.’

‘The Spanish throne is not a reward, it is a curse.’

Napoleon struck him on the shoulder, hard. ‘Ungrateful fool! Is that how you repay me?’

Joseph stared hard at his brother, eyes narrowing slightly. He took a deep breath to calm himself and spoke in an undertone. ‘Did I ask for the crown of Spain? No. You forced it on me. And I forced it on the people of Spain. Now they revile me for it, almost as much as they revile you.’ Joseph’s shoulders drooped as he clasped his hands together. ‘It is hopeless, I tell you.’

‘It is never hopeless. Those are the words of a coward,’ Napoleon replied coldly.

‘No, they are the words of a reasonable man who knows when the game is up.’ Joseph stiffened his posture. ‘I have made my decision, my brother. I will abdicate from the throne. I will leave Spain and retire to my estates in France.’

There was a brief silence before Napoleon turned away and clasped his hands behind his back. When he spoke again it was in a strained voice. ‘You will not abdicate. I forbid it.’

‘You cannot forbid it.’

‘I forbid it. What is more I will have you treated as a deserter if you ever leave Spain again without my express permission.’

‘A deserter?’ Joseph could not help smiling thinly. ‘You would have me shot?’

‘That is the fate of deserters,’ Napoleon replied coldly. ‘Though you are my brother, and I love you, I would have you put up against a wall and shot without the slightest compunction.’

‘I don’t believe you.’

Napoleon turned round, his stare piercing and merciless. ‘Believe it.’

Before Joseph could reply, his brother’s face creased in a sudden expression of agony and he staggered a pace towards Joseph before sinking slowly on to the path, propping himself up on one hand as he gasped for air.

‘Napoleon!’ Joseph crouched down beside him, supporting his shoulder. ‘What is it? What’s the matter?’

‘My stomach . . .’ Napoleon hissed through clenched teeth. ‘Christ, it hurts.’