King John had no accurate knowledge of his enemy's dispositions. In spite of the coming and going of the day before, he still knew no more than the fact that somewhere two or three miles ahead down the road, and between him and Nouaillé, the Black Prince's force was gathered. He appears to have made no effort to grasp things in greater detail upon that Monday morning, and when he marshalled his host and set out, it was with the intention (which he pursued) of merely going forward until he found the enemy, and then attacking. The host was arranged in four bodies; three main "battles" or lines, comparable to the English three lines--it was the universal formation of a mediæval army--were brought up in column for the advance, to deploy when the field should be reached. The first was commanded by the heir to the throne, the Dauphin, Charles, Duke of Normandy; the second by the Duke of Orleans, the king's brother; the third was commanded by the king himself, and was the largest of the three.
The attempt to estimate the numbers which John could bring against his enemy as he set out on that Monday morning is beset with difficulties, but must nevertheless be made.
Froissart, with his quite unreliable and (let us be thankful) romantic pen, speaks of over 40,000. That is nonsense. But it is not without some value, because, like so many of Froissart's statements, it mirrors the tradition of the conflict which future years developed. If we had no other figures than Froissart's we should not accept them, but we should accept, and rightly, an impression of great superiority in numbers on the part of the attack.
On the other hand, we have the evidence of a man who wrote from the field itself, and who wrote from the English side--Burghersh. If anything, he would exaggerate, of course; but he was a soldier (and Froissart was at the other psychological pole!). He actually wrote from the spot, and he thought that everything mounted in front of him came to about 8000, to which he added 3000 men upon foot. Now, Burghersh may have been, and probably was, concerned to mention no more than what he regarded as fighting units worth mentioning: infantry more or less trained and properly accoutred men-at-arms. For these latter, and their number of 8000, we have plenty of independent testimony, and especially Baker's. Baker gives the same number. As regards the trained infantry, we know that John had 2000 men armed with the arbalest (a mechanical cross-bow worked with a ratchet), and we know that he also had, besides these cross-bowmen, a number of trained mercenaries armed with javelins.