The single theme of the play is revenge. The theme appears in many different aspects of the plot, with varying degrees of moral justification. It is introduced at the very beginning, when the ghost of Andrea wants revenge on Balthazar for having killed him in battle, although there is nothing the ghost can directly do to bring it about.

The next character who wants revenge is Bel-Imperia, whose desired victim is also Balthazar, since he killed her lover, Andrea. Initially, she plans to use Horatio as her means of vengeance, and when Horatio is murdered, she has a double motive for revenge.

The third example of the desire for revenge is Balthazar, who wants revenge on Horatio for taking him prisoner in battle and being an obstacle to Balthazar's attempt to win Bel-Imperia.

The last and most important example of the revenge theme is Hieronimo, who...