Joseph paused in mid-stride and turned to his brother. ‘You think it is that simple, brother? I think you overestimate the soundness of our position in Spain. We are fighting a new kind of war in the Peninsula. In order to control the country we have to disperse our troops to police every town, village and road. It is the only way to keep the people in check. Yet whenever Wellington advances we are forced to concentrate our forces and abandon control over the countryside. And if we advance against Wellington with an army large enough to overwhelm him, he simply gives ground, luring us on, to the limit of our supply lines, until we are forced to give up the pursuit. And then we have to pacify the countryside all over again. I tell you, we will lose the war in Spain. While our numbers are whittled away, the enemy grows ever stronger. Our soldiers have been pushed out of Portugal and the British are poised to seize all the frontier fortresses and invade Spain.’

Napoleon shook his head. ‘Wellington is not strong enough to launch an invasion. He has no more than a fifth of the number of men available to you. Besides, I think you overrate his ability. He is the same as all the other British generals - too cautious to cause us much trouble. He cannot afford to lose any men. The longer the war goes on, the more certainly the English army will be frittered away. Besides, he lacks the experience of my marshals. Before he arrived in Portugal he commanded very modest forces out in India. I hardly think that a general of sepoys would be capable of besting the commanders of the finest army in Europe.’

‘Yet that is precisely what Wellington has done,’ Joseph countered. ‘He has beaten Junot, Jourdan, Soult and now Masséna. He is a man to be reckoned with.’

‘As I said, you overrate him. I have read the reports of those battles Wellington claims as his victories. He did not win them, he simply allowed our commanders to lose them through their recklessness. That is all. Hardly a firm basis upon which to build such a reputation as you would ascribe to him, Joseph. I tell you he can, and will, be beaten.’

‘Then why don’t you test yourself against him?’ Joseph stared at his brother intently. ‘The Army of Spain needs you, Napoleon. The men’s spirits are low. They have suffered too many reverses at the hands of that cursed English fox and their nerves are worn down by the bands of peasants that dog them wherever they march. The men are a long way from France, from home, and they can see no end to the war they wage in the Peninsula. They say that they have been forgotten by their Emperor.’