As dawn broke across the river the full extent of the damage done by the French engineers was clear for all to see. Only the odd pile that had been driven into the river bed still protruded from the glassy surface of the Douro. Downriver the banks on both sides were littered with scorched and shattered lengths of timber and here and there a beached pontoon. Arthur regarded the scene stoically. The bridge had gone, and now his army would either have to march upstream to find a crossing place, or wait until the Royal Navy could be summoned to transport them across the mouth of the river.That possibility held its own risk as Soult would hotly contest any such landing.

On the far bank a party of French soldiers had climbed down to the water and stripped off their uniforms for a morning swim.Their excited cries could just be heard as they splashed each other in full view of the redcoats stuck on the other side of the river. Above the bank the tiled roofs of the city rose up the slope, crowding the narrow winding streets. Most of the buildings facing the river had been occupied by French soldiers, some of whom could be seen leaning on window sills, contemplating the opposite bank as they puffed on their pipes.

Arthur frowned. It was exceedingly frustrating. There was no prospect of a direct assault across the river without enduring heavy losses. But by the time they crossed upstream, Soult could have slipped away towards Galicia; or, worse still, he might steal a day’s march on Arthur and head south towards Lisbon or Badajoz to link up with Marshal Victor. In either case, the tables would have been turned on the British.

As he stared across the river an officer came trotting across the terrace towards him and drew up breathless to stand stiffly to attention. Arthur recognised him as one of the Portuguese-speaking officers serving under Beresford.

‘Colonel Waters, isn’t it?’

‘Yes, sir.’

The man’s face was flushed with the effort of clambering up the hill to the convent, and his expression was animated as he drew sharp breaths to enable him to speak clearly.

‘Beg to report, sir ... I think I have found a way ... to get across the Douro.’

‘What’s that? How?’

Waters turned and pointed upriver, to where the Douro curved round the steep cliffs opposite, just beyond the building Arthur had briefly observed the evening before.

‘Just there, sir. I was down there this morning, scouting along the river bank looking for any boats the enemy might have missed. That’s when I encountered a barber.’

‘Barber? What nonsense is this?’