The English noblemen, gathering before the Battle of Agincourt, realize that the French outnumber them five to one. Westmorland wishes that they had with them some of the men who sit idle in England. But King Henry, entering and overhearing him, disagrees. In his famous St. Crispin’s Day speech (so called because he addresses his troops on October 25, St. Crispin’s Day), King Henry says that they should be happy that there are so few of them present, for each can earn a greater share of honor.

Henry goes on to say that he does not want to fight alongside any man who does not wish to fight with the English. He tells the soldiers that anyone who wants to leave can and will be given some money to head for home. But anyone who stays to fight will have something to boast about for the rest of his life and in the future will remember with pride the battle on this day. He adds that every commoner who fights today with the king will become his brother, and all the Englishmen who have stayed at home will regret that they were not in France to gain honor upon this famous day of battle. The soldiers and noblemen are greatly inspired, and morale rises dramatically.

The French are now ready for the battle. Montjoy, the French messenger, comes to the English camp one more time, asking King Henry if he wants to take the last opportunity for peace and surrender himself for ransom, instead of facing certain defeat in battle. Henry rejects the offer in strong though courteous terms, and the English organize and march into battle.

As the battle rages across the field, Pistol takes a French prisoner. The scene is comic: Pistol, who cannot speak French, tries to communicate with the Frenchman, who cannot speak English. Fortunately, the boy is present. He speaks very good French and is able to translate, though the hotheaded Pistol makes communication difficult. The terrified soldier is convinced that Pistol is a nobleman and a ferocious fighter.

The French soldier, who gives his name as Monsieur le Fer, says that he is from a respected house and family and that his relatives will give Pistol a rich ransom if Pistol will let him live. Pistol is very interested in money and accepts this bargain, and the grateful Frenchman surrenders as a willing captive. As the boy follows them offstage, he complains about Pistol’s empty boasting, saying that Bardolph and Nim both had ten times as much real courage in them as Pistol. The boy reveals a surprising and unsettling fact: Nim, like Bardolph, has been hanged for stealing.

The French camp is in disarray, and the French soldiers’ cries reveal that, against all expectations, the English have won the day. The French troops have been routed and scattered. Astonished and dismayed, the French nobles bewail their great shame and contemplate suicide. But they decide that rather than surrender in shame and defeat, they will go down fighting and return to the field for one final attempt.

King Henry’s inspirational St. Crispin’s Day speech—so called because the battle is fought on the feast day of St. Crispin, a holiday in the England of the play—is perhaps the most famous passage in the play. In this speech, which is meant to bolster the morale of his soldiers before they head into a battle that they are almost certain to lose, Henry demonstrates his customary brilliance with words and astounding charisma, both of which he has displayed so often before.

Henry’s challenge is to turn his troops’ small numbers into an advantage, which he does by convincing his men that the battle is more than a mathematical formula, that they have all come there to fight for honor, for justice, and for glory. He makes fighting with him at Agincourt sound like a privilege, one that will allow its participants to capture more glory than anything else could. Henry also brings up, once more, the motif of the bond between king and commoner. As in Act III, scene i, before the Battle of Harfleur, he unites himself with his men, saying,

Henry claims that even a commoner will be made noble by fighting at his side and that the result will be lifelong honor that will elevate these fighters above their peers.

The comic scene of Pistol’s capture of a Frenchman plays on language in much the same way that the earlier scene of Catherine’s English lesson does. Pistol’s misunderstandings of French, like Catherine’s of English, are amusing. He takes the soldier’s exclamation, “O Seigneur Dieu!” (“O Lord God!”), for a name and mistakes the words “bras” (“arm”) and “moi” (“me”) for “brass” and “moy” (a unit of measurement). Pistol must rely on the boy to translate for him, and, ironically, the boy shows himself to be better informed than the man he serves.

In the jaws of defeat, the French noblemen at long last recognize the power of the English combatants. When they realize that their troops have been scattered and defeated, their first reaction is one of overwhelming shame. But the nobles show a hitherto unprecedented courage when they decide to return to the fight instead of surrendering, as they might, and giving themselves up to be ransomed. This last show of courage on the part of the French adds a welcome new dimension to Shakespeare’s characterization of different nationalities and prevents his portrayal of the French from becoming a one-dimensional mockery motivated only by patriotic loyalty to England.