The English general had now to choose between a march down the left bank of the Ebro to seek a battle; or to place the army on the great communication with France, while the fleet, keeping pace, furnished fresh depôts at Bilbao and other ports. The first was an uncertain operation, because of the many narrow and dangerous defiles which were to be passed; the second was secure even if the first should fail; but both were compatible to a certain point; for to gain the great road leading from Burgos to Bilbao, was a good step for either, and, failing of that, there was a road leading by Valmaceda to Bilbao in reserve. Wherefore with an eagle’s sweep Wellington brought his left wing round, and poured his numerous columns through all the deep narrow valleys and rugged defiles towards the great road of Bilbao. At Medina de Pomar, a central point, he left the sixth division to guard his stores and supplies, but the march of the other divisions was unmitigated; neither the winter gullies, nor the ravines, nor the precipitous passes amongst the rocks, retarded the march even of the artillery; where horses could not draw men hauled, when the wheels would not roll the guns were let down or lifted up with ropes; and strongly did the rough veteran infantry work their way through those wild and beautiful regions: six days they toiled unceasingly; on the seventh, swelled by Longa’s Spaniards, and all the smaller bands which came trickling from the mountains, they burst like raging streams from every defile and went foaming into the basin of Vittoria.
During this movement many reports reached the French, some absurdly exaggerated, as that Wellington had one hundred and ninety thousand men, yet all indicating the true direction of his march; and as early as the 15th, Jourdan, warning Joseph that the allies would turn his right, pressed him to place Reille at Valmaceda and close the other armies towards the same quarter. Joseph yielded so far, that Reille was ordered to concentrate at Osma and gain Valmaceda by Orduña if it was still possible; if not he was to descend rapidly upon Bilbao, and rally Foy’s division and the garrisons of Biscay upon his army: but no general decided dispositions were made.