Richard II is the son of the Black Prince, a military hero and larger-than-life figure in English history. But Richard, who ascended to the throne at age 10, is very different from his father. He enjoys the privileges and power that come with the kingship but is an ineffective ruler. He taxes, borrows, and takes money to give his friends positions of power and to pursue expensive and ill-advised military actions. Richard is king at a time when kings are thought to be ordained by God and answerable to God alone. He is deeply invested in this idea and in playing the role of king—taking on a regal air and speaking in poetic and beautiful language full of metaphor and imagery. It takes him a long time to realize the appearance of kingliness is not enough to retain the crown. By then it is too late: Henry Bolingbroke has eclipsed him in popularity and power and forces Richard to cede the throne.
In stark contrast to the theatrical and regal Richard II, Henry Bolingbroke is assertive and straightforward—a man of action rather than words or grand gestures. In the play's first scene he accuses Thomas Mowbray of treason and conspiring to murder the Duke of Gloucester. After Richard banishes him from England, Bolingbroke defies the king and cuts his banishment short after Richard seizes his dead father's lands and wealth. Bolingbroke returns to England with an army, gains supporters, corners Richard, and forces the king to abdicate the throne. He takes on kingly authority even before he wears the crown, quickly trying and sentencing Richard's favorites and having those who plot against him executed.
John of Gaunt
In his younger days John of Gaunt was a powerful man who helped guide his nephew, Richard II, in the early years of his rule. Now Gaunt is an old man who believes strongly in the divine right of kings but is conflicted because he realizes Richard is an incompetent and destructive leader. He also knows Richard was behind the death of Gaunt's brother, the Duke of Gloucester. As he nears death, Gaunt displays a heartfelt and deeply emotional love for England, which he compares to the Garden of Eden; this love, and his proximity to death, embolden him to unleash frank criticism of Richard's governance.
Duke of York
The Duke of York is fiercely loyal to his nephew, Richard II. Knowing this, Richard leaves him in charge while he is away in Ireland. York unfailingly takes Richard's side—that is, until he doesn't. When it becomes clear Bolingbroke will be king, York somewhat reluctantly joins Bolingbroke's rebel army. It seems his loyalty is to the monarch, whomever that may be—not to any particular man. This is akin to Gaunt deciding his loyalty lies more with England than with its king. After York switches his allegiance to Bolingbroke, he seems eager to prove his loyalty, quickly turning on his son, the Duke of Aumerle, who is plotting the new king's murder.