The rivalry between Prince Hal and Hotspur drives much of the main plot--a rivalry much intensified by Shakespeare's changing of Hotspur's age to make him a peer of the prince, rather than a member of the older generation.

Hotspur's main function in the plot is to represent the rebels and their ambitions, but he is a powerful and attractive character in his own right, forgiven for his outspoken behaviour because of his fiery commitment to honour--though his view of honour could possibly be confused with pride, or hubris.