Much of Henry IV, Part One has to do with the king's power struggle against the Percys, a noble family who once supported him but who now accuses him of arrogance and ingratitude. Yet that aspect of the play which is perhaps most interesting to modern audiences is the conflict that occurs between a father (King Henry) and his oldest son (Prince Hal).

Henry IV repeatedly expresses his disappointment with his first-born son, who spends his time in "rude society," frequenting taverns and brothels when he should be at court or on the battlefield preparing himself to succeed his father as king (III.ii. 14). So dissatisfied is the king with Hal that in I.i.86-90 he openly wishes it might somehow turn out that Hotspur and Hal had been switched at birth, and that the brave and clean-living Hotspur were in fact his son and...