Prince Harry, sometimes known as Monmouth, is the same as the Prince of Henry IV, Part One.
Despite his apparent reformation in that play, he has since the battle of Shrewsbury gone back to his disreputable ways, playing pranks on Falstaff, mocking Poins, consorting with prostitutes and tavern-keepers. He has even been sent to prison after being publicly disorderly and slapping the Lord Chief Justice in court. He spends much less time with Falstaff, however, beginning to neglect him and preparing for his rejection once he takes the throne. Despite what King Henry and the whole world believes, he loves his father, but he is aware that saying so would have him tagged as a hypocrite because of his past conduct. He is extremely concerned about how he appears to the world, due to his master plan of setting himself up as a wastrel so that his reputation will be enhanced when he gives up that behavior on taking the throne. He is very quick to pick up the crown when he thinks that his father is dead; though he insists he did so to get used to the idea of kingship, his excuses are undercut by the fact that they are spoken in retrospect, and do not fully match what the audience saw on stage. As he is extremely successful at playing roles, the truth behind his feelings remains unknown. As King, he tests the loyalty of the Lord Chief Justice to make certain that fear of his new power will not undercut the old man’s honesty. His rejection of Falstaff and rounding up of his old companions has exactly the effect that he planned it to. Both as Prince and as King it is difficult to discern what his genuine emotions are; whether casting off his dissipation causes him any pain is up to the performer. Taking his father’s last words of advice, he plans a war in France to occupy his noblemen’s minds and energies and thus forestall rebellion. How this turns out can be discovered in Henry V.