The English long bowmen fired barrage after barrage of arrows high into the air over the mass of Frenchmen. Arrows fired high came down with tremendous force, each arrow having a sharpened iron arrowhead known as a bodkin point.
Naturally, there is great historical debate over what happened at Agincourt. Experiments have been conducted which prove, or disprove, that the English arrows could penetrate French armor although the ones I have seen on YouTube and elsewhere don’t seem to account for the parabolic effect of the flight of the arrow and the additional force that would give the arrow as it fell.
While the arrows may, or may not have, been able to penetrate the steel armor of the richest nobles, they could penetrate chain mail. (Foot soldiers and lower ranking nobles on foot rarely wore more body protection than chain mail). Further, and more disruptive, the lack of protection horses had from the rain of English arrows was a “game changer.”
An armored knight on a steed was a powerful “weapons system” but unhorsed, he couldn’t move very quickly. In fact, without help, he couldn’t get back on his feet. Killing or disabling a mounted knight’s horse with a flight of arrows would hardly have been difficult.
Without his horse, a medieval knight wearing the battle armor of a mounted man, and not the lighter armor of a man expecting to fight on foot, would have been easy to neutralize since once unhorsed, his mobility was almost zero. Given the visor which covered his eyes except for a tiny slight, he would have difficulty seeing anything not directly in front of him.
An interesting theory claims that numbers of French men-at-arms who were attacking on foot were apparently killed in a classic crowd disaster. There were rank after rank of these men. When crowds press forward into a small space, the force generated begins to create a huge jam of people with more and more force being exerted by people in the back continuing to push forward. This asphyxiates those jammed into the small space who get pushed together so tightly they cannot move — or breathe. The force is also enough to break bones.
If this indeed happened to the thousands of Frenchmen on foot then while they were being jammed together so tightly they could not breath, and their armor plate was no doubt breaking the bones and spines of the men in front of them, it might explain why literally thousands and thousands of Frenchmen died.
According to a research paper by John J. Fruin, Ph.D., P.E. The Causes and Prevention of Crowd Disasters:
AGINCOURT WAS PROBABLY ONE OF THE WORST CROWD CRUSH INCIDENTS IN THE WESTERN WORLD
When the Frenchmen began to endure this horror, panic would have set in, which would only have increased the intense force pushing the men together as some tried to go forward and others backward. Into the midst of this panicked crowd, the English bowmen were shooting upwards of 50,000 arrows a minute. They didn’t aim at individuals. They just fired masses of arrows into the air so they would come down in an arc onto a crowd.
figure above is from Medieval Character Models. (Arrows would have gone through the chain-mail)
There were 5,000 plus English archers and they could fire about ten arrows a minute. They were well trained although physical exhaustion would have led to a slackening of fire after a time. If you have ever fired a bow and arrow for just a few times you become aware of the muscle power required.
Still, whatever the pack of French knights and men at arms were trying to do, they were doing it under a hail of deadly arrows. And only the wealthiest men could afford the best steel armor which could not be penetrated by English arrows. Only a handful would have been wearing armor like that. Most would have had inferior armor and chain mail which the English arrows could and did penetrate.
French casualties were said to be in the thousands against a handful of English dead and the French who survived their calamitous defeat left the battlefield in shock defeated in mind and spirit.
From Henry V. After the slaughter of the French knights and gentlemen on foot, the French herald comes and informs Henry that he has won a great victory.