In ‘My Last Duchess, the Duchess is killed by the Duke for her failure to recognise his status within society, and his ‘nine-hundred-years-old name’ (l. 33) that she possesses because of him. Her disrespect of the title, and her ability to be ‘too easily impressed’ (l. 23) insults the Duke. The Duke implies that the Duchess was fickle and did not meet the standards of his high-ranking family, as she was pleased by all things, such as a ‘bough of cherries’ (l. 27) and a ‘white mule’ (l. 28). This leads to the Duke giving ‘commands | Then all smiles stopped together’ (ll. 45-46). The abrupt nature of line 46 demonstrates the speed of the death of the Duchess following the Duke’s order and makes for dramatic reading. The caesura caused by the phrase, in the middle of line 46, also gives the reader a moment to digest the barbarity of the Duke’s actions, which were motivated by his wish to preserve his status. Status influences the deaths of both female characters in the poems, albeit it in different ways. The Duchess’ failure to recognise her newfound status leads to her downfall. Here Browning may be criticising the idea of social mobility, as for the Duchess it ends in death.
The Duke’s possession in relation to the Duchess is explored by his keeping of her image ‘painted on the wall | Looking as if she were alive’ (ll. 1-2). This personification of the painting emphasises the detail within it, as well as the Duke’s desire to hold his wife in an infinite moment. The painting is kept behind a curtain so that only the Duke can access and make an exhibition of her, when he pleases. This demonstrates his possessive nature towards his wife, and his desire to capture her in a perfect moment as if she were living. The use of the word ‘my’ throughout the poem, and in the title, emphasises the possessive nature of the Duke towards his wife. Emily Francomano correctly summarises that, for the Duke, ‘true love is equivalent to the complete control that can only be attained by the deaths of the women they desire.’ This can also apparent in Brownings other work, ‘Porphryia’s Lover.’ Both women are victims of the desire of their male counterparts, specifically the desire to possess them fully.
The Duke’s killing of his wife is motivated by egoism. Browning ends the poem using an exclamatory phrase in which the Duke describes a statue of Neptune. The Duke casually finishes his tale, about the murder of his wife, and swiftly moves on, downplaying its significance. This alarms the reader, as the Duke appears unremorseful for the role he played in his wife’s demise, and more concerned with himself. The Duke is presented as a figure who lacks ‘human affection,’ as he killed the Duchess for egotistical reasons: the protecting of his own status.
The Duke feels considerable contempt towards the Duchess, and when this emotion reaches its peak, he orders for her to be killed. The dramatic shift in tone can be seen in the poem, signifying the peak of the Duke’s hatred for her, as he vows ‘Never to stoop’ (l. 43). This short dramatic sentence encapsulates the strength of the Duke’s contempt and a shift in the tone of the poem. It is clear that the Duke considers himself to be of greater moral standing than the Duchess, prompting him to have her killed. This action abruptly ends their relationship.
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 Robert Browning, ‘My Last Duchess’, in The Norton Anthology of Poetry, ed. by Margaret Ferguson, Mary Jo Salter, and Jon Stallworthy, 6th edn (London: Norton, 2018), pp. 1061-1062.
 E. Francomano, ‘Escaping by a Hair: Silvina Ocampo Rereads, Rewrites, and Re-Members “Porphyria’s Lover”’, Letras Femeninas, 25 (1/2) (1999), pp. 65-77, 65.
 J.R Watson, ‘Robert Browning: ‘My Last Duchess’, Critical Survey, 6(1/2) (1973), pp. 69-75, 74.