Duke Gloucester uses manipulation, patience, and murder to become King Richard III of England.
In 1471 King Edward IV (Ian Hunter) holds old King Henry VI (Miles Mander) a prisoner in the tower. Henry learns that Lord Devere (John Rodion) is to be executed. John Wyatt (John Sutton) pleads with Queen Elizabeth (Barbara O'Neil) for Devere, who calls Edward a usurper and warns Wyatt of Richard, Duke of Gloucester (Basil Rathbone). Mord (Boris Karloff) chops off Devere's head, and Richard pays him. Richard is jealous of Wyatt with Alice Barton (Nan Grey). King Edward asks Richard to marry the Duchess of Norfolk; but Richard suggests Wyatt, who refuses because he loves Alice. Edward puts Wyatt in the tower, though Queen Elizabeth complains he is her cousin; Edward promises not to kill Wyatt but banishes him. Richard tells Edward that King Henry could be killed in battle. Richard sends Mord to spread rumors that Henry supports King Edward, and Mord intercepts Queen Elizabeth's message to Wyatt. At the battle of Tewksbury in the rain Richard kills Hereford, but King Henry is cheered. Richard gives Mord a knife to murder Henry. Richard sends Mord to arrest hiding Ann Neville (Rose Hobart). Richard pretends to take her side. King Edward will not release Ann unless she marries Richard, and she agrees. Edward's child is wed to a child, and Richard's engagement is announced. Duke of Clarence (Vincent Price) complains that Richard should not get half of the Warwick estate and warns Edward. Clarence plots and is arrested by Mord. Richard challenges his brother Clarence to a drinking contest for all of Warwick, but Richard and Mort drown Clarence in the cask.
In France in 1483 Henry Tudor (Ralph Forbes) and John Wyatt learn that King Edward is ill. Dying Edward tells Lord Hastings (Leo G. Carroll) to recall Wyatt to marry Alice. Edward appoints Richard protector of his son King Edward V (Ronald Sinclair). Richard has Edward V's brother Richard (John Herbert-Bond) join the king in the tower. Queen Elizabeth tells Hastings she mistrusts Richard. People shout they want Richard as king, but he is coy. Wyatt returns to Alice, and Queen Elizabeth in sanctuary asks him to steal the royal treasure. His men do so. Richard accuses Wyatt and has Mord torture him, demanding to know where the treasure is. Alice sneaks into the tower with chimney sweep Tom Clink (Ernest Cossart). Wyatt tells Alice to get the treasure; he files his chain and escapes. Mort tells Richard, who orders the princes arrested in the tower. Mord has King Edward V and his brother murdered. Henry Tudor thanks Wyatt and Alice for the money. In the battle at Bosworth Henry Tudor fights Richard and kills him and Mord. In the final scene Wyatt and Alice are wed.
This drama tells the traditional history of Richard
III's ruthless ambition as portrayed by the Tudor dynasty that
replaced the Plantagenets. The quest for power proves to be a
very dangerous game.