Kingship and Morality
Like many of Shakespeare's history plays, Henry V is interested in exploring the responsibilities, limitations, and nuances of power and leadership. The play calls into question what it means to be a "good" king, portraying Henry as both a ruthless leader (his claim to the French throne is tenuous) and yet an effective one. In many ways, the play suggests that history's best leaders (and England's best kings) have also been self-interested and power-hungry. However, this quality, as embodied by Henry V, does not seem to be mutually exclusive from one's ability to lead.
Warfare
War serves as the entire backdrop of Henry V as the play follows Henry's invasion of France and his success at the famous Battle of Agincourt. Critics are generally divided on whether the play is more interested in portraying war as necessary and effective or devastating and destructive. Thus, the play is rather ambivalent about the nature of war, instead presenting both perspectives: Henry seeks glory and strength for England through the war, while the soldiers he interacts with in disguise are simply interested in surviving and making it home to their families. If anything, the play presents war as a totalizing event, one that thrusts people of different social classes and motivations together for a common goal.
Growth and Maturation
The play begins with characters discussing the radical change that Henry has undergone since becoming king. No longer the reckless "Hal" of his boyhood (as detailed in Shakespeare's other history plays), Henry V is now an ambitious, driven, and generally responsible king. One could argue, however, that part of the reason for Henry's effectiveness as a ruler is due to his whimsical past, and furthermore that he has not entirely outgrown his predilection for games and debauchery. When Henry dresses up to walk among the common soldiers, for example, he invites the audience to remember his days of playing dress-up and causing mischief with Falstaff (see Henry IV). This scene also, however, lends him insight into the experiences of the common solider, insight that helps him become a more calculated and informed leader. Thus, though Henry has grown into a well-respected leader, the play suggests that his past was not entirely abandoned but simply put to better use as a mature king.
England's Diversity
One element that stands out about Henry V among most of Shakespeare's history plays is its portrayal of England's diverse population. While history plays (and, for that matter, the majority of Shakespeare's plays in general) concern themselves exclusively with royalty and nobility, Henry V paints a portrait of England as a melting pot of nationalities and social classes. The interplay between English, Scottish, Irish, and Welsh characters (and their corresponding languages) reminds audiences that "England" as an empire is already a composite nation. Furthermore, Henry V presents its "commoner" characters – like the soldiers – as valuable interlocutors with meaningful perspectives, even if they will never be on equal footing with their king.
Language
Related to the play's interest in England's diversity is its portrayal of language and communication. While language typically plays an important role in Shakespeare's work – his greatest villains are also his best rhetoricians – Henry V seems more invested in using language, and language difference, as an emblem of both misunderstanding and tolerance. Large portions of the play are spoken in French, a choice that would alienate any non-French speakers in Shakespeare's audience, but even the characters themselves are seen struggling with the language barrier that exists between them. In many ways, the play's focus on language reveals its commitment to portraying the labor that must be applied in order to bridge gaps between citizens of different nationalities. The play is surprisingly democratic in its representation, likely reflecting the efficacy of Henry V as a leader.
The Theater
Throughout the play, the Chorus reminds the audience that the space they have provided is insufficient for portraying history with great accuracy. The Chorus therefore consistently thrusts the audience out of the typical suspension of disbelief necessary for watching a play on the early modern English stage. By calling attention to the theater itself, the play emphasizes the importance of appearances within the narrative while also encouraging audiences to acknowledge the relationship between the theater and the history is represents. After all, the play was being performed in England about a not-too-distant English history. The self-conscious remarks by the Chorus remind audiences of the connection between past and present.
Memory
It is the nature of history plays to have some investment in memory and the past, as they are plays primarily concerned with notions like narrative, legacy, and what came before. Henry V is no different, especially as it is the final play in a four-part cycle that includes Richard II, Henry IV, Part One, and Henry IV, Part Two. There are numerous references to these plays throughout Henry V, suggesting that Henry is as conscious of the history that preceded him as he is driven to forge a legacy for himself as the king of England and possibly France. Furthermore, the relevance of the past is also deeply personal, as Henry must relinquish his wild past in order to rule effectively. This means having to leave his old friends behind (like Falstaff) and making decisions based on justice and leadership rather than affection. Still, some have argued that Henry's dressing up as a common soldier suggests that he does not entirely eschew his wild past but instead uses it in a new way to rule more effectively.
