What is the main conflict in My Last Duchess by Robert Browning?

The conflict revolves arounds the Duke's attitude to women. Using abundant detail, Browning leads the reader to conclude that the Duke found fault with his former wife because she did not reserve her attentions for him, his rank, and his power. More importantly, the Duke's long list of complaints presents a thinly veiled threat about the behavior he will and will not tolerate in his new wife.