The Duke's Introduction to the Portrait: The dramatic monologue opens with the Duke of Ferrara showing a visitor—a representative of a Count whose daughter the Duke intends to marry—a portrait of his late wife, the Duchess. The Duke invites the emissary to sit and observe the painting, which is displayed behind a curtain. This curtain, the Duke explains, is something only he can draw, emphasizing his control over who views the Duchess even after her death.
The Duchess's Joyful Disposition: As the Duke begins to describe the Duchess, he reveals his dissatisfaction with her personality. He criticizes her for being too easily pleased and for showing joy and gratitude to everyone around her, regardless of their social standing. The Duke was offended that she treated his "nine-hundred-years-old name" with the same casual appreciation she gave to a sunset or a simple gift. He felt that her appreciation for all things, including trivial matters, was an insult to his noble status.
The Duke's Inability to Confront the Duchess: The Duke then reflects on his inability to confront the Duchess about her behavior. He imagines what it would have been like if he had spoken to her directly, telling her that her actions were displeasing to him. However, the Duke believes that to stoop to such a level—to ask her to change—would have been beneath his dignity. Instead, he chose to remain silent, allowing his resentment to grow.
The Final Command: The Duke's disdain for the Duchess’s behavior culminated in a chilling revelation. He "gave commands" that resulted in the Duchess’s permanent silence, implying that he had her killed to stop her from continuing to offend him with her indiscriminate kindness and joyful demeanor. The Duke’s words are cold and detached as he describes how all her smiles "stopped together," a phrase that suggests a calculated and deliberate act to end her life.
The Duke's Attention to Art and Wealth: After revealing the fate of his former wife, the Duke smoothly transitions back to the present, inviting the emissary to join him in meeting the other guests. He casually mentions the dowry expected from the Count, suggesting that he is confident in his ability to secure a favorable marriage arrangement. The Duke insists that his primary interest is in the Count’s daughter, not the financial gain, though his earlier discussion of wealth and status casts doubt on this claim.
The Duke’s Final Display of Power: As they prepare to leave, the Duke points out a bronze statue of Neptune taming a seahorse, crafted specifically for him by Claus of Innsbruck. This statue serves as a final symbol of the Duke's obsession with control and his desire to dominate all aspects of life, from his relationships to his possessions.