With Robert Browning's use of dramatic monologue, the Duke of Ferrara paradoxically creates a portrait of himself while he describes Fra Pandolf's portrayal of his first duchess. For one thing, the breathlessness of the duke's speech clearly betrays his own feelings of pride and jealousy:
She thanked men,—good! but
Somehow—I know not how—as if she ranked
My gift of a nine-hundred-years-old name
With anybody's gift. Who'd stoop to blame
This sort of trifling?
The use of the dashes indicate the racing heartbeat of the jealous husband who has just described how his first wife had
A heart—how shall I say?—too soon made glad,
Too easily impressed: she liked whate'er
She looked on, and her looks went everywhere.
Choosing "never to stoop" to pleading with his wife, the duke "gave commands" and then "all smiles stopped together." In his arrogance, the duke has had his wife killed; then, in the decadence of a "nine-hundred-years-old name," he mounts his kill in the form of a painting, a painting that from which only he can draw the curtain.
Displaying this work of art pleases the vain and worldly duke as he points to how "she stands/As if alive." Finally, on the descent of the Duke and the envoy down the stairs, the duke speaks of the dowry of the Count's daughter, his "object," and Ferrara points to a sculpture of Neptune that he commissioned Claus of Innsbruck to sculpt. There, the god of the sea tames a sea horse just as the proud duke has "tamed" his first duchess.
Clearly, therefore, the Duke of Ferrara is an exceedingly proud, jealous, arrogant aristocrat who is preoccupied with possessions and determined to have his will satisfied.