In Act II, Scene III of Richard III, a group of English citizens express concern about the future of the nation following the death of King Edward IV. With his heir, Edward, Prince of Wales, still a child, they understand that a Protector will be named to govern on his behalf until he is old enough to rule. They are aware that several of the prince's uncles are competing for this role, and they fear that the ensuing power struggle will plunge the country into chaos. Having already suffered through the tumultuous Wars of the Roses, where the Houses of York and Lancaster battled for control of the throne, they yearn for stability and peace. Unfortunately, they are faced with Richard instead.

The issue of succession, which dictates the lawful and rightful ascent to the monarchy, was a significant concern for the people of England during Shakespeare's era. Their queen, Elizabeth I, was aging, unmarried, and without an heir. Although she was the rightful queen, Elizabeth had faced numerous challenges to her authority, including from Philip II of Spain, who launched the Spanish Armada in 1588 in an attempt to overthrow her, and from Mary, Queen of Scots, a relative whom Elizabeth was forced to execute in 1587. Consequently, a play about an ambitious nobleman seeking the throne held great relevance for Shakespeare's audience.

Richard is a usurper; he seizes the throne unlawfully and realizes that if he does not at least seem to be the legitimate ruler of England, he will face continuous challenges to his authority. The series of murders Richard commits both before and after becoming king can be viewed as efforts to legitimize his reign.

Among the three brothers—King Edward IV, George, Duke of Clarence, and Richard, Duke of Gloucester—Richard is the youngest and furthest from the line of succession. Clarence is ahead of him and could also be named Protector of Edward's heir, the Prince of Wales, if King Edward were to die. Therefore, when the king falls gravely ill, Richard schemes to eliminate Clarence first, thereby removing both a potential Protector and a rival claimant to the throne in one fell swoop.

Richard's next step is to ensure that he alone becomes the Protector of his nephew, the Prince of Wales. To achieve this, he gets rid of Rivers, the prince's uncle on his mother's side, and also murders Lord Grey, the prince's half-brother. (The prince's other half-brother, the Marquess of Dorset, manages to escape and joins the Earl of Richmond.)

Once Richard becomes the undisputed Protector, it becomes simpler for him to seize the throne. He eliminates Hastings because Hastings has pledged loyalty to Prince Edward's claim to the crown. By casting doubt on the legitimacy of the Prince of Wales and his younger brother, the Duke of York, Richard and Buckingham persuade the public that Richard is the sole rightful and virtuous candidate for kingship.

Even after ascending to the throne, Richard is aware that his authority remains vulnerable as long as the Prince of Wales and the Duke of York are alive. Despite being imprisoned and kept out of sight, these two legitimate heirs of King Edward could still inspire discontented or ambitious individuals. Consequently, Richard makes the grim decision to eliminate the young princes.

Despite these actions, Richard still feels insecure. He imprisons Clarence's son because the child has a stronger claim to the throne, and he marries Clarence's daughter to a commoner to eliminate any potential royal contenders from that lineage. Eventually, Richard learns that his adversary, the Lancastrian Earl of Richmond, plans to marry Edward IV's daughter, Elizabeth, to unite the York and Lancaster families. In an effort to thwart this union and bolster his own claim, Richard seeks to marry King Edward's daughter himself. This is why, in Act IV, scene iv, he attempts to persuade Queen Elizabeth to agree to the marriage.

Richard's efforts to cement his power through violence ultimately fail when he is slain in battle by the Earl of Richmond, who ushers in a new line of succession—the Tudors—and is crowned Henry VII.