Please give an explanation of the following lines from "My Last Duchess" by Robert Browning.
Or there exceed the mark”—and if she let
Herself be lessoned so, nor plainly set 40
Her wits to yours, forsooth, and made excuse,
—E’en then would be some stooping; and I choose
Never to stoop. Oh sir, she smiled, no doubt,
Whene’er I passed her; but who passed without
Much the same smile? This grew; I gave commands
You have managed to select the heart of this poem, and some of the most disturbing lines ever written in literature, in my opinion. These lines tell us the fate of the poor last Duchess, and how her completely indifferent husband had her murdered because of his own arrogance and inability to compromise. Looking at these lines in context, we can see that the Duke is such a proud man that he considers it beneath himself to discuss with his wife what was annoying him about her actions and his own jealousy. His refusal "Never to stoop" indicates that he believes he is such an important man that he thinks he should have his wants anticipated and met without ever having to "stoop" to ask for anything or to express his discontent.
It was the inability of the last Duchess to do this that led her to carry on "smiling" and offending her husband, which in turn led to the vague "commands" of her husband, which resulted in her death. The Duke is clearly presented as a man who will not brook any opposition to his powerful will, and as a tyrannical individual.