A horse! a horse! my kingdom for a horse!"
Edward IV sits on the throne of England, but his brother Richard seeks to rule England himself. Richard does not hesitate to remove anyone in his way—including his brother George, whom he has murdered. He improves his chances at the throne by strategically and heartlessly pursuing and marrying Anne, widow of the Prince of Wales, King Henry VI's heir.
News of George's death hits an already ailing Edward IV very hard, and he dies. Under the thinly-veiled guise of “protecting” them, Richard—serving as Regent to the throne while the royal heir comes of age—has Edward's children confined to the Tower of London. Edward's wife, Elizabeth, sees through Richard's malicious intentions. Her husband's supporters Vaughan, Rivers, Hastings and Grey are imprisoned and executed. Even Richard's mother comes to understand her son's tyrannical intentions.
Richard does have one ally—the Duke of Buckingham, who helps Richard declare that his deceased brother's offspring are not legitimate heirs to the throne. Buckingham helps stage a public offering of the throne to Richard, who feigns reluctance to accept. Buckingham, however, balks when asked to kill the young boys in the Tower, and flees in fear. His fears are founded as he is later captured and killed. Richard's conspiracy to solidify his claim to the throne is deepened when (after the convenient death of his wife Anne) he marries his own niece, Elizabeth, daughter of Edward.
As Richard manipulates the kingdom for his own purposes, Henry Tudor, Earl of Richmond and the last Lancastrian heir, prepares to lead an army from France against Richard. The night before the two sides are to meet in battle, Richard is haunted in his dreams by the ghosts of his victims. After his death the next day in battle at the hands of Richmond, Richmond is crowned Henry VII right on the field of battle. He announces his own marriage to Elizabeth. This marks the founding of the Tudor line and the end of the War of the Roses.