One of the most notable aspects of Henry IV, Part I is the ongoing transformation that Prince Henry, called Hal, undergoes. For much of the play, King Henry’s attitude toward his son ranges from annoyance to the edge of despair. Hal always plays around, drinking in taverns with Falstaff, and his father seriously doubts that the youth is future king material. The king thinks that Hotspur (Henry Percy) is a better example of what an upstanding son should be—until young Percy sides with the rebels against him.
The older Henry IV had to prove his worth in a very challenging situation. When King Richard’s misrule mired England mired in chaos, Henry stepped up and led the opposition. To one way of thinking, his actions constituted treason against Richard II. Henry decided it was his moral obligation and civic duty to act against him. Yet the damage that Richard caused ran deep, and did not end with his death. Other opposition forces are joining together to contest Henry’s rule.
Young Hal has never been tested in this way. His father’s authoritative personality, as well as his position as king, are very intimidating, but Hal does not want to admit his fears. He says that all his goofing off is just a ruse to throw people off, and he does have the mettle to act as a noble warrior. His father finally confronts him, wondering what he did to deserve a son who wastes his time in satisfying “inordinate and low desires,” through “lewd,… mean attempts… [in] rude society” (Act III, Scene 2). He goes on at great length about what he endured, and how he rose to the occasion, in challenging Richard. Hal makes a “solemn vow” to best Hotspur in battle, and thus fulfill his duty as a son and an Englishman. And ultimately, he does.