A vast number of vehicles, loaded with the whole imperial and royal treasure, overspread the plain and choked the great road behind the French position, by which alone such a mass of waggons could find its way into France. The French army consisted of about 60,000 men, with 150 pieces of cannon, but strong detachments, under Foy and Clausel respectively, had been sent away to guard the roads to Bilbao and Pamplona. The British army numbered nearly 80,000, inclusive of Portuguese and Spanish, with 90 guns. The French were posted on strong ground, and held the bridges across the river. Graham, with the left column of the British, made a circuit in the direction of Bilbao, working round to cut off the French rear on the Bayonne road. Hill, with the right column, forced the pass of Puebla, in the latter direction, carried the ridge above it after much hard fighting, and made good his position on the left flank of the French. Wellington himself, in the centre, under the guidance of a Spanish peasant, pushed a brigade across one of the bridges in his front, weakly guarded, and thus mastered the others; his force then expanded itself on the plain and bore down all opposition. Graham had met with a more obstinate resistance from the French right, under Reille, but at last got possession of the great Bayonne road. Thenceforward a retreat of the French army, partly encircled, became inevitable, but it was conducted at first in good order and with frequent halts at defensible points. The only outlet left open was the mountain road to Pamplona, and this was not only impracticable for heavy traffic but obstructed by an overturned waggon. The orderly retreat was soon converted into a rout; the flying throng made its way across country and over mountains towards Pamplona, leaving all the artillery, military stores, and accumulated spoils as trophies of the British victory.