Power
The central theme of almost all of Shakespeare's history plays, power appears in Richard II as a distinct and debatable notion between two sides. Allies of Richard perceive kingship as that which is always inherited and passed down through blood (more specifically, fathers to sons). However, supports of Bolingbroke see power as a more amorphous phenomenon, granted to the king by his subjects rather than inherited. As such, Bolingbroke's side believes that an undeserving, irresponsible, or otherwise poor ruler can be stripped of their crown, even if it was inherited through blood. This debate about the nature of power reflects the changing political landscape of early modern England (when Shakespeare was writing), as conceptions of the monarchy were beginning to shift more toward secular understanding rather than religious – that is, kings were no longer considered divine descendants but instead fallible people who derived their power from the people they were supposed to lead.
Familial Bonds
The majority of history plays are not only about political machinations but about family ties as well, as most notable political players in English history were related. Indeed, Richard II and Henry Bolingbroke are themselves cousins, and their feud showcases the difficulty of navigating a monarchical system in which power and family are inextricable. Furthermore, the play prompts its audience to question whether political aspiration should be secondary to familial ties; the female characters in the play nearly always align themselves with their families, while the same cannot be said of the male characters (a fact that introduces another important theme, gender, to the play).
Gender
By virtue of English history itself, history plays are notably masculine performances that feature conflicts among men all vying for power. Women are typically on the periphery of these plays, and Richard II is no exception. However, the female characters in the play, despite their obvious lack of power or influence, do serve an important role in developing the performance's deeper questions: women always choose kinship over power, prioritizing familial relationships over political aspiration. This tendency raises the question of which is more important – family or politics – for the overall health of the English nation. In later plays of the tetralogy, female characters (still relatively powerless) develop into vehicles of personal and familial memory, opposing political machination with the power of familial connection and remembrance.
Pride
Richard II is an undeniably proud ruler. Indeed, the play establishes early on that his pridefulness is likely his greatest flaw as a king: finding himself akin to a divine sovereign, Richard II makes no attempts to rule his subjects with care, believing his throne indisputable based on his inheritance. As such, he squanders England's money on his own entertainments and fails to perform the necessary duties of the king. All the while, Richard accuses others like Bolingbroke of being too proud, an ironic assertion given his own political failings and self-absorption. The play ultimately suggests that Richard's pride is what leads to his downfall, as he is unable and unwilling to see his own faults.
Language
A common theme among all Shakespeare's plays, language appears in Richard II as intimately entwined with power. Richard himself believes that his language is synonymous with power, and indeed at the beginning of the play he is correct: as the king of England, his requests are heeded without question. But, after Richard is deposed, his words become meaningless against the actions of Henry Bolingbroke. Bolingbroke, by contrast, acknowledges that he is not much for language or rhetoric; instead, he is associated with action and behavior that grant him opportunities to seize power. Richard's rhetorical skill (his speech about his fall is one of the most eloquent among Shakespeare's plays) does not appear to serve him in the battle for monarchical supremacy, and the play suggests that language without action can lead to a weak or faulty reign.
Machiavellianism
In his treatise The Prince (1532), Niccolo Machiavelli details a political philosophy now known simply as Machiavellianism. Tenets of Machiavellian leadership include political deceit, optics, and ruthlessness. Regarding Richard II, some maintain that the rise of Bolingbroke signifies Shakespeare's representation of Machiavellian leadership in England: Bolingbroke sneaks back into England from his exile, silences Richard's supporters immediately, and makes Richard give up all his monarchical accessories to enforce the fact that he is no longer king. These decisions, some scholars argue, showcase a nascent Machiavellian philosophy that would have begun to take shape during Shakespeare's own time (as Machiavelli died only a few decades before Shakespeare was writing).
Loyalty
The play showcases and interrogates numerous kinds of loyalty – political loyalty, familial loyalty, circumstantial loyalty, loyalty to the law, etc. Because the political landscape of the play is inextricable from familial conflict, characters are often put in the position of choosing between loyalty to their kin and loyalty to their king (or the king's challenger). Others express loyalty not to a person but to an office: York, for example, is loyal to the office of the king, regardless of who sits on the throne. As mentioned, the female characters in the play side with their families no matter the circumstances. And finally, Richard II himself believes that he deserves the loyalty of the people without having to extend any loyalty of his own. All these competing loyalties are precisely what create the drama of the play, and the performance prompts the audience to question whether one form of loyalty is more effective or moral than another.