‘What is Cole doing?’ Arthur muttered. ‘Why doesn’t he cover his flank?’ He turned hurriedly to Somerset. ‘Send a message to General Cole and warn him to watch his left flank. And tell Pack to send one of his brigades forward to take the hill.’

‘Yes, sir!’

As Somerset wheeled away Arthur watched anxiously as the Fourth Division halted and began to exchange fire with the third of the French formations. So intent was Cole’s concentration on the target to his front that he had clearly missed the danger to his left. Arthur could see that the enemy had realised the chance they had to take sweet revenge on the redcoats in precisely the same manner as they had suffered. But before they could strike, General Pack’s Portuguese doubled forward and began to clamber up the slope towards the crest of the Greater Aparil. It was a desperate attempt to win time for their British comrades, and they were outnumbered by an enemy who held the high ground. The attack stalled as the French skirmishers unleashed a withering fire down the slope. Arthur watched with growing anguish as Pack’s men stopped and went to ground, and then started to fall back.

‘Time for the reserves,’ he decided. Wheeling his horse about, he galloped across the ridge to where the men of the Sixth Division were waiting on the reverse slope, hidden from the battle. General Clinton sat on his horse at the head of his men and tipped his hat as Arthur rode up and reined in breathlessly.

‘Clinton, I want your fellows to advance directly. They are to take the large hill to your front. The enemy must be driven from it and across the valley.’

‘Yes, sir.’ Clinton nodded. ‘You can rely on us. The boys have missed enough of the excitement as it is.’

‘Then I am glad to be of service,’ Arthur smiled. Then his expression hardened. ‘Remember, drive the enemy off the hill.’

By the time he had returned to his command post Arthur was shocked to see that fresh French formations were descending from the Greater Arapil, directly towards the left flank of the Fourth Division. General Cole was finally alert to the danger and had begun to wheel the battalion at the end of his line to face the danger. But one battalion would not be enough, Arthur could see at once. Within the next few minutes his fears were borne out as the French line halted and opened fire, cutting down swathes of men in the thin red line opposing them.