Hotspur’s accusations in this scene are somewhat hypocritical, since he seems to imply that his father, Northumberland, only helped Henry to power because he believed that Henry would not overthrow the rightful king (“he heard him swear and vow to God / He came but to be Duke of Lancaster” [IV.iii.62–63]). The reality is, of course, somewhat more complicated, however, and it seems that Northumberland and the other Percys must have known perfectly well from the outset that Henry wanted to become king. Their choice to throw their power behind Henry in a claim to lands being held by King Richard could owe only to their confidence that Henry would overtake Richard, for if Henry were to fail, they would face serious retribution from King Richard. The complexity of the characters’ mixed political motivations seems to cast doubt on Hotspur’s own claim that he and his family have gathered their current army only in order to preserve their own safety.
Hotspur’s statement that the rebels may decide to accept Henry’s offer of peace is rather unexpected given Hotspur’s generally warlike character. It is completely at odds with his vow in the preceding section to fight Harry to the death. It is also an important point to bear in mind when Shakespeare reveals, in Act V, that Worcester is keeping certain facts from Hotspur because he fears that his nephew will be inclined to settle the debate peacefully. Worcester, not wanting a peaceful solution, thus secretly squelches any opportunity for Hotspur to follow through on the rational impulse that he shows in this scene.
The Archbishop of York’s only appearance in 1 Henry IV occurs in this scene, whose purpose is to set up plot threads that extend into the next play in Shakespeare’s sequence—2 Henry IV. We do not learn much about what the archbishop’s letters contain, but their effects imply that plots are being laid that will continue to haunt Henry even after the Battle of Shrewsbury concludes. Indeed, when the battle has scarcely ended, in Act V, scene v, Henry must almost immediately divide and disperse his forces again—half northward toward York and Northumberland, where the archbishop and the one remaining Percy are arming themselves, and half to Wales to deal with Glyndwr and his rebels.