From my theory, the reason why the emperor and the duke have such bad relationship is definitely because the emperor was obsessed with the duke's lover (the lady with green eyes).
There is high possibility that the emperor somehow kidnapped the duke's lover and did the "unspeakable" resulting in Ellie, and prissoned her in the castle.
As for the duke, he doesn't know what happened and though that her lover just left him.
Meanwhile, Ellie's thief mother is possibly the loyal maid to Ellie's mom.
And then, the red hair queen killed Ellie's mom, and The maid run away saving baby Ellie.
The queen probably does not know that Ellie was born. But she know that the maid witnessed her killing Ellie's mom.
That's why the queen searched and killed the maid (the thief).
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Maybe my imagination is too wild...
Ohh i didn't know about the maid, I thought it was the empress's sister (the green eyed possibly Ellie's mother) she said it in the latest chapter and i think that caused her hatred for green eyed women grew strong because the king choose her sister as his concubine and got so obsessed. You're theory is interesting too
No, no, I don't know about a "maid" either...
This is just my speculation.. lol....
The empress killed every woman who has green eyes and the duke of shuetz wife had green eyes? How did her wife died again?? I forgot. Also i think Ellie's mother also had a green eyes so the empress is the one who planned everything to get her killed