Bad as was the position selected, the way in which it was occupied was still more strange. The Captain-General had divided his host into two halves, the one consisting of the first division of the army of Galicia and of the vanguard brigade, the other of the fourth Galician division and the raw ‘Army of Castile.’ Blake with the first-named force was drawn up in a short, compact formation, three lines deep, at the south-eastern front of the hill, the ‘Plateau of Valdecuevas,’ as it is called. His right looked down into the plain, his left, in the centre of the plateau, stood quite ‘in the air.’ But nearly a mile to his left rear, and quite out of sight, lay the other half of the army, just too far off to protect Blake’s exposed flank if it should be attacked, and in a very bad position for defending itself. Why Cuesta ranged his left wing (or second line, if it may so be called) low down on the reverse slope of the plateau, and in a place where it could not even see Blake’s corps, it is impossible to conceive. Toreño hazards the guess that, in his arrogant confidence, he placed Blake where he would have to bear the stress of the battle, and might probably lose ground, intending to come up himself with the left wing and restore the fight when his colleague should be sufficiently humbled. Such a plan would not have been outside the scope of the old man’s selfish pride.
Bessières, marching up from the east, came in sight of the Spaniards in the early morning. He at once deployed his whole army, and advanced in battle array over the plain. In front was a slight cavalry screen of Lasalle’s chasseurs; next came Mouton’s division, deployed to the right, and Merle’s division, with Sabathier’s brigade, to the left of the country-road which leads, over the plateau, towards Medina de Rio Seco. The Imperial Guard, horse and foot, and the bulk of Lasalle’s cavalry brigade were in reserve behind the centre. On getting near the enemy’s position, Bessières soon discovered the two halves of the Spanish army and the broad gap which lay between them. His mind was at once made up: he proposed to contain Cuesta with a small force, and to fall upon and envelop Blake with the rest of his army before the Captain-General of Castile could come to his aid. This excellent plan was carried out to the letter, thanks to the incapacity of Cuesta.
Not far east of the plateau of Valdecuevas lay an isolated eminence, the mound of Monclin: on it the marshal drew up the greater part of his artillery (twenty guns) which began to batter Blake’s front line: the Galician batteries replied, and held their own though outnumbered by two to one. Then Sabathier’s eight weak battalions deployed and commenced a cautious attack upon Blake’s front: this was not to be pressed home for a time. Meanwhile Merle’s seven battalions pushed into the fight, continuing Sabathier’s line to the south-west and trying to envelop Blake’s southern flank. They forced the Galicians to throw back their right wing, and to keep continually extending it, in order to avoid being turned. The Spaniards fought not amiss, and for some hour or more the battle was almost stationary.
Meanwhile, far to the French right, Mouton’s five battalions were executing a cautious demonstration against Cuesta’s forces, across the northern folds of the plateau. The old general allowed himself to be completely occupied by this trifling show of attack, and made no movement to aid Blake’s wing. The gap between him and his colleague was not filled up. Then came the sudden development of Bessières’ plan: Sabathier and Merle were told to attack in earnest, and while Blake was deeply engaged with their fifteen battalions, Lasalle rode into the open space on the left of the Galicians, formed up the 22nd chasseurs à cheval at right angles to the Spanish line, and charged in furiously upon Blake’s flank. The unfortunate troops on whom the blow fell were deployed in line, and utterly unprepared for a cavalry shock from the side. The first battalion which received the attack broke at once and ran in upon the second[137]: in a few minutes Blake’s whole left wing fell down like a pack of cards, each corps as it fled sweeping away that next to it. The French infantry, advancing at the same moment, ran in with the bayonet, seized the Spanish guns, and hustled the Galicians westward along the plateau in a mob. Blake’s troops were only saved from complete destruction by the steadiness of a Navarrese battalion, which formed square to cover the retreat, and at the cost of one-third of its strength allowed the other corps to get a long start in their flight. They retired due west, and crossed the Sequillo to the south of the town of Rio Seco before they could be rallied.
It was now the turn of Cuesta to suffer. The moment that Blake was disposed of, Bessières marched over the hill towards the other half of the Spanish army: leaving some of Lasalle’s cavalry and Sabathier’s brigade to pursue the routed corps, he formed the whole of his remaining troops in a line, bringing up the reserve of the Imperial Guard to make its centre, while Mouton formed the right wing and the two brigades of Merle the left. Cuesta, outnumbered and attacked down hill, would have done wisely to retreat and to seek for shelter in and behind the town of Rio Seco in his immediate rear. But he had prepared a new surprise for the enemy; as they descended upon him they were astonished to see his front line, the eight battalions which formed the fourth Galician division, form itself into columns of attack and slowly commence to climb the hill with the object of attacking their right and centre. Meanwhile Cuesta’s handful of cavalry rode out on the northern end of the line and fell upon the skirmishers of Mouton’s division, whom it chased back till it was met and driven off by the three squadrons of the Imperial Guard.
The uphill charge of the fourth Galician division was a fine but an utterly useless display of courage. They were attacking nearly double their own numbers of victorious troops, who outflanked them on both wings and tore them to pieces with a concentric fire of artillery to which they could not respond. The regiments at each end of the line were soon broken up, but in the centre two battalions of picked grenadiers[138] actually closed with the French, captured four guns of the Imperial Guard, and forced back the supporting infantry of the same corps for a short space, till Bessières hurled upon them the three squadrons of the Guard-Cavalry, which broke them and swept them down hill again.
Seeing his attack fail, Cuesta bade his last reserve, the raw Castilian and Leonese levies, retreat behind the river and the town of Medina de Rio Seco, which they did without much loss, covered to a certain extent by the two Asturian battalions, the only part of Cuesta’s own force which was seriously engaged.
The ‘Army of Castile,’ therefore, had no more than 155 casualties, but the two Galician divisions had suffered heavily. They left behind them on the field nearly 400 dead, and over 500 wounded, with some 1,200 prisoners. The ten guns of Blake’s wing had all been captured, and with them several pairs of colours. In addition more than a thousand of the Galician recruits had dispersed, and could not be rallied. Altogether Blake’s army had lost over 3,000 men. The French, as might have been expected, had suffered comparatively little: they had 105 killed and 300 wounded, according to Foy; other historians give even smaller figures.