The English army met the French on October 25, 1415, near the village of Agincourt in northern France. Henry V had marched his men from Harfleur and was outnumbered, perhaps by three or four to one. The French expected an easy win. They were wrong.
The ground was narrow and muddy. Henry placed his archers on the flanks, and when the French knights advanced, the longbows cut them down. The mud slowed the charging horses, and the tight field turned the French numbers into a trap. Knights piled up and could not move. The longbow had changed war.
The numbers tell the story. Modern estimates put the English at around 6,000 to 9,000 men, mostly archers, against a French force of 12,000 to 36,000, many of them armored nobles, and the French lost several thousand including many high-ranking lords while English dead numbered only in the hundreds. Agincourt did not end the war, but it gave England a strong hand at the talks that followed.
The victory secured Henry's claim in France and fed the legend of the warrior king. Shakespeare later made Agincourt the centerpiece of a play. The battle is still taught as the day foot soldiers beat cavalry. French pride took a long time to recover, and the loss of so many nobles weakened the French crown at a bad moment for the king.