On October 25, 1415 — England was at war with France during the latter part of the 100 years war, and King Henry V had led his men into France after negotiations broke down following a relative peace between the two countries. It was in this battle that several important observations could be made about warfare. First, it is thought by many that it was at this battle that chivalry died. Second, it proved the effectiveness of the English longbow against the overwhelming numbers and odds they faced.

After the invasion of France by Henry V, the English decided after a few months on the campaign that they would head back to England, and were marching back to the French town of Calais to be taken back to England across the English channel. That was when they were blocked by the French at Agincourt. King Henry V decided it best to stand and fight as it was thought the French had reinforcements on the way to add to the already overwhelming numbers in strength the French had that day.

On October 25, the French army attacked. However, due to the mud from the field being both currently plowed and soaked from a recent rain, the French had mobility trouble due to their numbers and better armor. They were slaughtered by the English and many French were taken prisoner. They had effectively demonstrated the efficiency and lethality of the English longbow. However, both weather and terrain were a significant factor in the English victory. The French were forced into somewhat of a funnel from which they could not escape given the number of men charging towards the English in the mud. Their armor did not make it any easier as they were easy targets for the English and whoever was able to escape the longbow were killed or captured by the English. It was a stunning defeat for the French.

After taking prisoners, Henry ordered the execution of many high ranking prisoners contrary to the chivalric code, in which the norm at that time was to take the prisoners back to England for ransom. Before the battle, it was customary for knights, nobles, and other high ranking members to be taken prisoner for ransom. A good ransom would have been a considerable amount of money for the common soldier in the English army, however, and perhaps given that the English were already outnumbered Henry ordered the execution of the French prisoners. This is thought by many to be the end of chivalry.