The Spanish officer’s eyes narrowed. ‘If you are truly an ally of my country, then you would help us, señor. Even so, my general has sent for help from the army of Andalucia. General Alvarez, he promise to send his cavalry to help the English raise the siege. You need not have fear of the French horse, señor. General Alvarez deal with them.’

‘Is that so?’ Arthur’s expression hardened. ‘And what is the strength of General Alvarez’s cavalry?’

‘Five thousand sabres, señor.’ The captain stiffened his weary back and stared at Arthur haughtily. ‘The finest cavalry in Europe.’

Arthur did not respond immediately. He had been promised much by Spanish generals in the past, only to be disappointed when their promises had proved worthless. Their bad faith had cost the British army dearly during the Talavera campaign and he had vowed not to make the mistake of taking them at their word again. It grieved him that the Spanish people, and the common soldiers, were patriots and prepared to defy Bonaparte whatever the cost, yet their senior officers were utterly unreliable. In all likelihood, General Alvarez would never make any attempt to raise the siege. Even if, by some miracle, they did march on Ciudad Rodrigo his men would be scattered by the first enemy formation that barred their way.

Taking a deep breath, Arthur leaned forward and met the Spanish officer’s contemptuous gaze directly. ‘I would ask you to convey my profound regret to General Herrasti. Tell him that I am unable to lift the siege. Tell him that if I were to attempt it, then it is possible that our enemy would inflict a defeat on the one allied army in the Peninsula that stands any chance of defying Bonaparte. I cannot afford to squander what slim hope we have of driving French troops from Spain in the future. Is that understood?’

‘Yes, señor. I understand that perhaps the English are as Napoleon says - you cannot trust them. And that they will fight to the very last drop of Spanish blood.’

Somerset gasped. ‘Now, that’s—’

‘Quiet!’ Arthur snapped. He glared at his aide for a moment before turning his attention back to the Spaniard. ‘I apologise for my subordinate’s lack of self-discipline.’ He rose coolly and offered his hand. ‘There is nothing more I can say, Captain, except good luck, to you and your general.’

The Spaniard did not take his hand, but bowed his head briefly and turned to stride out of the tavern, stumbling slightly at the entrance as exhaustion got the better of his haughty demeanour. Then he was gone, and Arthur immediately rounded on Somerset. ‘What the devil did you think you were doing? British officers have a reputation for imperturbability and discipline, Somerset. I’d be obliged if you reflected on that and make sure that you do not damage that reputation.’

‘Yes, sir.’ Somerset shuffled uncomfortably. ‘Is that all, sir?’