It matters little where these dreadful doings took place; all round Poitiers there are wide plains where armies might have encountered; but it would seem probable that the spot where the battle so fatal to France was really fought, must have been situated so as to have afforded the handful of English some signal advantage; or how was it possible for a few hundred exhausted men to conquer as many thousands! The English crossbows, which did such execution, were most likely stationed at some pass in the rocky hills of which there are many, and their sudden and unexpected onset must have sent forth the panic which caused the subsequent destruction of the whole French army.
In fact, Froissart describes their position clearly enough.

He names Maupertuis as a place two leagues to the north of Poitiers, and the spot chosen by the Black Prince as a hill full of bushes and vines, impracticable to cavalry, and favourable to archers: he concealed the latter in the thickets, connected the hedges, dug ditches, planted pallisades, and made barricades of waggons; in fact, formed of his camp a great redoubt, having but one narrow issue, guarded on each side by a double hedge.

At the extremity of this defile was the whole English army, on foot, compact and sheltered on all sides; while, behind the hill that separated the two armies, was placed an ambuscade of six hundred knights and cross-bowmen.
The French army was divided into three parts, and disposed in an oblique line.

The left and foremost wing was commanded by the king's brother, the Duke of Orleans, the centre by the king's sons, and the reserve by the unfortunate monarch himself.

Already the cry of battle was heard, when two holy men rushed forward to mediate between the foes; but in vain.