Ferdinand, the Duke of Calabria

Ferdinand is the twin brother to the Duchess. He is perverse and turbulent, according to Antonio. Ferdinand asks his sister if Bosola can be the horse manager and bribes Bosola to spy on the Duchess in his new job. Originally Ferdinand thinks that Antonio would have been a better fit for the job, but comes to understand from his brother that Antonio is too honest.

Ferdinand and his brother instruct and warn the Duchess not to remarry. Before he leaves the scene, he pulls out his father’s knife in front of his sister. Ferdinand is furious after finding out that his sister is pregnant. He gets out of control and speaks of killing her.

While visiting his sister, Ferdinand commands that she kills herself and hands her a knife. After the Duchess and Antonio find out they are banned, Ferdinand writes a letter...