Of the part taken by his battalion on this advance Colin Campbell kept a minute daily record, which has been preserved. He acted as orderly officer to Lieutenant-Colonel Crawford of his battalion, who commanded the flank companies of the third and fifth divisions in the operation of crossing the Esla at Almandra on May 31st. Continuing its march towards the north-east Graham's corps crossed the Ebro with some skirmishing, and on the morning of the 18th of June its advance debouched from the defile of Astri and marched on Osma, where the French General Reille with two divisions was unexpectedly met. Reille occupied the heights of Astalitz. The light companies of the first brigade were sent against the enemy, who were evincing an intent to retreat, and Campbell accompanied his company. He notes as follows:--"This being our first encounter of the campaign, the men were ardent and eager, and pressed the French most wickedly. When the enemy began their movement to the rear, they were constrained to hurry the pace of their columns, notwithstanding the cloud of skirmishers which covered their retreat. Lord Wellington came up about half-past three. We continued the pursuit until dusk, when we were relieved by the light troops of the fourth division. The ground on which we skirmished was so thickly wooded and so rugged and uneven, that when we were relieved by the fourth division, and the light companies were ordered to return to their respective regiments, I found myself incapable of further exertion from fatigue and exhaustion, occasioned by six hours of almost continuous skirmishing." On the 20th Wellington's army moved down into the basin of Vittoria. King Joseph's dispositions for the battle of Vittoria, which was fought on June 21st, were distinctly bad. His right flank at Gamara Mayor was too distant to be supported by the main body of his army, yet the safe retreat of the latter in the event of defeat depended on the staunchness of this isolated wing. Graham, moving southward from Murguia by the Bilbao road, was to attack Reille who commanded the French right, and to attempt the passage of the Zadora at Gamara Mayor and Ariaga; should he succeed, the French would be turned, and in great part enclosed between the Puebla mountains on one side and the Zadora on the other by the corps of Hill and Wellington.