“My Last Duchess” shows the corrupt power of a domestic tyrant. Browning uses this theme again in his longest poem, The Ring and the Book (1868-1869), in which the sadistic Count Guido kills his wife after falsely accusing her of adultery.
Spoken monologues often reveal more to the listener (and reader) than the speaker intends, but this arrogant aristocrat has no hesitation. The Duke of Ferrara obviously considers himself superior to others and above laws and morality. He clearly states that he gave the commands that stopped his wife’s smiles altogether. After all, he tells the agent, “she liked whate’er/ She looked on, and her looks went everywhere.” The duke was irritated by such behavior and had it eliminated. He uses his power to get others to do his will, including, presumably, the agent. As he had others eliminate his wife, and as he had a painter and a sculptor create objects of art to his specifications, he assumes that the agent will provide the kind of duchess he wants. He seems unconcerned about any hesitations a potential second wife might have about how his first marriage ended. He appears confident his demands will be met, both the ample dowry and the subservient wife.
The jealousy and possessiveness that seem to accompany the duke’s assertion of power suggest that he will be equally suspicious of any living wife, and indeed the portrait of his last duchess is more satisfactory to him than was the duchess herself. He can open or close the curtain as he pleases; he can exert complete control.
Browning’s genius created a character whose own words condemn him and show him as a ruthless, corrupt man who misuses his power. What makes the Duke of Ferrara especially horrifying is that he feels no repentance and no need for repentance. There have been no checks on his abuses of power thus far, and there is nothing to suggest that he will not continue his egotistical and tyrannical ways.