Lines 45-46
This grew; I gave commands;
Then all smiles stopped together.
• The Duke claims that "This grew" (45) – that is, the Duchess's indiscriminate kindness and appreciation of everything got more extreme.
• The Duke then "gave commands" (45) and as a result "All smiles stopped together" (46).
• Our best guess is that he had her killed, but the poem is ambiguous on this point.
• It’s possible that he had her shut up in a dungeon or a nunnery, and that she’s as good as dead.
• She’s not his Duchess anymore – she’s his "last Duchess" – so she’s clearly not on the scene anymore.
Lines 46-47
There she stands
As if alive. Will’t please you rise?
• The Duke ends his story of the Duchess and her painting by gesturing toward the full-body portrait again, in which she stands "As if alive" (47)
Lines 47-48
We’ll meet
The company below, then.
• The Duke invites his listener to get up and go back downstairs to the rest of the "company."
• As in line 5, this sounds like a polite invitation – but we can’t imagine anyone refusing.
Lines 48-53
I repeat,
The Count your master’s known munificence
Is ample warrant that no just pretence
Of mine for dowry will be disallowed;
Though his fair daughter’s self, as I avowed
At starting, is my object.
• We finally learn why the Duke is talking to this guy: his listener is the servant of a Count, and the Duke is wooing the Count’s daughter.
• The Duke tells the servant that he knows about the Count’s wealth and generosity, or "munificence" (49), so he expects to get any reasonable dowry he asks for.
• But his main "object" (53) in the negotiations is the daughter herself, not more money.
Lines 53-54
Nay, we’ll go
Together down, sir.
• The Duke’s listener seems to try to get away from him (we would try, too).
• The Duke stops him and insists that they stay together as they go back to meet everyone else downstairs.
Lines 54-56
Notice Neptune, though,
Taming a sea-horse, thought a rarity,
Which Claus of Innsbruck cast in bronze for me!
• Before the Duke and his listener leave the gallery, the Duke points out one more of his art objects – a bronze statue of Neptune, the god of the sea, taming a sea-horse.
• The Duke mentions the name of the artist who cast this statue, Claus of Innsbruck, who made it specifically for him.