Act One, Scene One
King Henry speaks with Westmorland about the fact that he has tried to lead a crusade to the Holy Land for over a year, but cannot due to the civil strife at home. He vows to end the civil wars within England. Westmorland, however, has news that Mortimer has been captured by the Welsh nobleman Glyndwr, and that he has married Glyndwr's daughter. This news is followed by positive news that Hotspur has defeated the Earl of Douglas up near Scotland and taken prisoners.
King Henry, although overjoyed by the news of the victory, is sad that his own son Harry, known affectionately as Hal, is a prodigal, spending time in taverns rather than fighting. He compares Hotspur, the son of Northumberland, with his son, and wonders whether they were switched at birth. "Then would I have his Harry, and he mine" (1.1.89).
Act One, Scene Two
Hal, who is the Prince of Wales, and his good friend Falstaff are in an apartment drinking and having fun. In dialogue laced with sexual innuendo, they speak about a tavern where both men like to flirt with the hostess. Their conversation turns to thieves, and Falstaff tells Hal that when he becomes the king he had better not hang a thief. Hal jokingly offers Falstaff the job of hangman for the thieves.
A thief named Poins enters, and soon he and Falstaff try to coax Prince Harry to join them in thievery. Hal reluctantly agrees, saying, "Well then, once in my days I'll be a madcap" (1.2.127). After Falstaff leaves, Poins tells him that they will play a trick on Falstaff. They plot to allow the other men, including Falstaff, to rob their target. After the robbery is complete, Hal and Poins will descend upon the robbers and rob them in return. Hal finally agrees to this, mostly for the anticipated fun of seeing Falstaff try to explain how he got robbed after committing his own crime.
Hal ends the scene with a brilliant soliloquy, saying, "I know you all, and will a while uphold / The unyoked humour of your idleness" (1.2.173-174). This soliloquy unmasks Hal, who tells the audience that he is only pretending to be a madcap prince. He claims that he is friends with the thieves in order to mask his true identity, which is that of a future king. "My reformation, glitt'ring o'er my fault, / Shall show more goodly and attract more eyes" (1.2.191-192). Thus Hal is hiding himself underground for now, but through his speech the audience knows that he will soon assume his rightful position as heir to the throne.
Act One, Scene Three
King Henry, Hotspur and Northumberland meet together. Henry is furious about the fact that Hotspur has refused to hand over the prisoners he captured in Scotland. Hotspur, in his defense, says that he previously refused to hand over the prisoners because he was still on the battlefield, and disliked the young man who demanded them in the king's name.
King Henry does not accept Hotspur's argument concerning the prisoners, and is equally upset that Hotspur's brother-in-law Mortimer lost the battle in Wales to Glyndwr. Henry believes that Mortimer is a traitor, a charge which Hotspur denies. However, there is a complication because Mortimer was also named by Richard II as his heir to the throne, which Henry IV usurped when he defeated Richard. After a final demand for Hotspur to release the prisoners into his custody, King Henry allows Hotspur and Northumberland to return home together.
Hotspur and Northumberland remain on stage after everyone exits. Hotspur tells his father that he will never release the prisoners, and that he will die trying to defend Mortimer's reputation. He even refers to Bolingbroke, King Henry's family name, implying that he does not recognize the legitimacy of Henry's claim to the throne.
Hotspur works himself into a frenzy about the injustices he is suffering, refusing to listen to Worcester or his father. Finally he calms down, and Worcester recommends that Hotspur deliver his prisoners to Henry, but make the son of Douglas his main ally in Scotland. He then tells Northumberland to make friends with the Archbishop of York, whose distant cousin Lord Scrope was killed by Henry. Together they plan to unite their armies in Scotland and York with Glyndwr's forces in Wales, and then overthrow the king by splitting England into three portions.
Henry IV, Part One begins with King Henry trying to make England peaceful again. His words at the beginning allude to an England with no more civil wars. However, this utopian dream of his fails immediately, and within a few lines we receive reports of war in Wales and Scotland. The effort to rule England without civil war is a dream which must be left to Henry's son Hal.
Hal is by far the most compelling character in terms of his depth. He is brilliant with language, having the ability to learn the language of others very quickly. He also has a gift for acting, and is therefore able to interact with the street ruffians in the taverns. Falstaff, his companion in crime, represents the base elements which Hal chooses to make friends with.
However, Shakespeare gives a very different picture of Hal almost immediately. At the end of the second scene we are introduced to a new Hal, and unexpectedly devious and cunning Hal who is fully aware that he will someday rule England. Hal is not a madcap, for he tells us that he is fact merely acting the part of the prodigal son so that he may shine all the brighter later on. "I know you all, and will a while uphold / The unyoked humour of your idleness" (1.2.173-174). In fact, the street life is a form of education for Hal, a man who is able to speak a tinkerer's language within fifteen minutes (2.5.15)
It is only with this inside knowledge of Hal's true character that we can understand his sarcastic allusions and comments differently from the other characters. For example, Hal remarks to Falstaff after his friend has ignored an older lord's advice that, "Thou didst well, for wisdom cries out in the streets, and no man regards it" (1.2.78). Hal clearly recognizes the old lord's wisdom, but is willing to pretend that it is of no regard. Even more interesting is when Hal tells Falstaff that, "Thou judgest false already" (1.2.57), alluding to Falstaff thinking he will be made a judge. This is not about being a judge though, it is really about Falstaff's knowledge of Hal.
The interactions between Falstaff and Hal lead to several moments of intense foreshadowing. For example, Falstaff tells Hal that, "By the lord, I'll be a traitor then, when thou art king" (1.2.130). This is in fact the case in Henry IV, Part Two, when Hal has Falstaff banished as soon as he is the king. This occurs later on in Act Three as well.
Hotspur, the young man whom King Henry wishes his son Hal would emulate, emerges as a central character in this act. What is most striking about Hotspur is the fact that he is a warrior, with a warrior's impulses. He belongs to the feudal times, with his hot temper and passions. His father Northumberland comments that often something "Drives [Hotspur] beyond the bounds of patience" (1.3.198). This impulsiveness will ultimately be what destroys Hotspur, who is an antiquated form of nobility. What becomes obvious is that Hotspur not only lacks Hal's manipulation of language, but also his ability to take over the best features of other men, something Hal does to Hotspur when he is able to take the words out of his dying mouth in Act Five.