What is beyond contention is the disparity within the English army. It was primarily an army of archers who, when they left England, outnumbered the men-at-arms by about three to one, but by St. Crispin’s Day had a preponderance of nearly six to one. You can find still more argument, endless argument, about how those archers were deployed, whether they were all on the flanks of the English army, or were arrayed between or in front of the men-at-arms. I cannot believe archers were placed in front, simply because of the difficulty of extricating them through the ranks before the hand-to-hand fighting began, and believe that the vast majority were indeed on the left and right of the main line of battle. A good discussion of archery in battle can be found in Robert Hardy’s terrific book, Longbow: A Social and Military History.
I have tried, as far as possible, to follow the real events that took place on that damp Saint Crispin’s Day in France. In brief it seems certain that the English advanced first (and it seems Henry really did say “let’s go, fellows!”) and re-established their line within extreme bowshot of the French army, and that the French, foolishly, left that maneuver uncontested. The archers then provoked the first French attack with a volley of arrows. That first assault was by mounted men-at-arms who were supposed to scatter and so defeat the feared archers, but those attacks failed, partly because horses, even wearing armor, were fatally vulnerable to arrows, and because of the stakes that formed enough of an obstacle to take any impetus out of the charge. Some of the retreating French horses, maddened by arrows, appear to have galloped into the first advancing French battle, causing chaos in its close-packed ranks.
That first battle, probably consisting of about 8,000 men-at-arms, already had severe problems. The fields of Agincourt had recently been plowed for winter wheat and it is true, as Nicholas Hook says, that you plow deeper for winter wheat than for spring wheat. It had also rained torrentially the previous night, and so the French were trudging through sticky clay soil. It must have been a nightmare. No one could hurry, and all the while the arrows were striking and, the closer the French came to the English line, the more lethal those arrow strikes were. There is more argument about the effect of arrows, with some scholars claiming that even the heaviest bodkin, shot from the strongest yew bow, could not pierce plate armor. Yet why else would Henry have so many archers? The arrows could pierce plate, though the strike had to be plumb, and undoubtedly the best plate, such as that made by the Milanese, was better able to resist. If nothing else the arrow-storm forced the French to advance with closed visors, severely restricting their vision.
A good archer could shoot fifteen accurate arrows in a minute (I’ve seen it done with a bow that had a draw-weight of 110 pounds, some twenty to thirty pounds lighter than the bows carried at Agincourt, but far heavier than any modern competition bow). Assume that the archers at Agincourt averaged a mere twelve a minute and that there were 5,000 bowmen; that means in one minute 60,000 arrows struck the French, a thousand arrows a second. It also means that in ten minutes the archers would have shot 600,000 arrows and the conclusion is that they must have run out of arrows fairly quickly. Yet what that storm of arrows achieved was to drive the flanks of the disordered French advance inward, onto the waiting English men-at-arms. That shrinking of the French line must have exposed the flanks of the English army, both composed of archers, to the French crossbowmen, but there is no evidence that the French seized the opportunity. Apart from a few volleys at the very beginning of the battle the French archers appear to have taken no part, a fatal error that must be ascribed to the abysmal lack of leadership on the French side.
The battle lasted between three and four hours, yet it was probably as good as over in the very first minutes when the leading French battle struck home. The French men-at-arms were weary, half blinded, disordered, and mud-crippled. What seems to have happened is that their leading ranks went down quickly and so formed a barrier to the men behind who, in turn, were being pushed onto that barrier by the rearmost men. So the French stumbled into the English weapons and the English (with some Welsh and a few Gascons) had more freedom to fight and to kill. That first French battle had contained most of France’s high nobility, and so it went to the slaughter and the great names fell; the Duke of Alençon, the Duke of Bar, the Duke of Brabant, the Archbishop of Sens, the Constable of France, and at least eight counts. Others, like the Duke of Orleans, the Duke of Bourbon, and the Marshal of France, were captured. The English did not have it all their own way; the Duke of York was killed, as was the Earl of Suffolk (his father had died of dysentery at Harfleur), but English casualties seem to have been remarkably slight. Henry undoubtedly fought in the front rank of the English and all eighteen Frenchmen who had sworn an oath of brotherhood to kill him were killed instead. Henry’s brother Humphrey, Duke of Gloucester, was badly wounded in the fight and it is said that Henry stood over him and fought off the Frenchmen trying to drag the injured duke away.
The second French battle went to reinforce the first, but by now the French were trying to fight across a barrier of dead and dying men, and they were also fighting the English archers who had abandoned their bows and were now wielding poleaxes, swords, and mallets. The advantage the English archers possessed was maneuverability; unencumbered by sixty pounds of mud-weighted armor they must have been lethal in their attacks. I cannot confirm that the British two-fingered salute began at Agincourt as a taunt to the defeated French, demonstrating that the archers still possessed their string fingers despite French threats to sever them, but it seems a likely tale.
Sometime after the advance of the second French battle a small force of horsemen, led by the Sire of Agincourt, attacked the English baggage. This event, and the apparent readiness of the remaining Frenchmen to attack, persuaded Henry to issue his order to kill the prisoners. That order appals us today, yet the contemporary chroniclers do not condemn it. By that stage there were around two thousand French prisoners close behind the English line that was half expecting an attack by another eight thousand, so far unengaged, Frenchmen. Those prisoners could well have swung the battle by assailing Henry’s rear, and so the order was given to the evident displeasure of many English men-at-arms (who were losing valuable ransoms). Henry sent a squire and two hundred archers to do the killing instead, though it was evidently stopped fairly quickly when it became apparent that the raid on the baggage did not presage an attack from the rear, and that the threat of the third French battle had evaporated. The French had taken enough, their survivors began to leave the battlefield, and Henry had won the extraordinary victory of Agincourt. Wild uncertainty surrounds the casualties, but undoubtedly the French suffered dreadful losses. An English eyewitness, a priest, recorded ninety-eight dead from the French nobility, around 1,500 French knights killed, and between four and five thousand men-at-arms. French losses were in the thousands, and might well have been as high as 5,000, while English losses were most likely as small as 200 (including one archer, Roger Hunt, killed by a gun). The battle was a slaughter that, like the sack of Soissons, shocked Christendom. It was an age inured to violence. Henry did burn and hang the Lollards in London, and he executed an archer for stealing the copper-gilt pyx during the march to Agincourt, but those events were commonplace. Soissons and Agincourt, uncannily linked by Saints Crispin and Crispinian, were thought extraordinary.