Answer :
An example of how Duke showed his jealousy in the poem is, “as if she ranked / My gift of a nine-hundred-years-old name / With anybody's gift”.
Duke is a character in a poem who is a noble who resides over a duchy (or dukedom) and holds the highest hereditary title of nobility.
From the quote “as if she ranked / My gift of a nine-hundred-years-old name / With anybody's gift”, the reader is able to understand that the Duke feels like his wife did not accept his lineage name and she did not deserve it. The Duke is jealous of the way the Duchess treats other people, not because he loves her and wants all her love for himself, but because he wants her to acknowledge his power over her.
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