It isn't actually that odd; the jailed heir is Robert's clever, ambitious brother who, knowing that he'd never become king with primogeniture succession and had to see his imbecile brother wear the crown, kept plotting against his brother Robert and rebelling against his father.
More:
The king of France's hausmacht consists of one sole barony. I think it happened because his father the king was deposed, but I don't know why he'd only have a barony. Maybe it's because the kingdom is elective?
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A female Khatun leading the Ilkhanate. She married the Khan of the Golden Horde and their son Ghazan eventually ended up merging the two hordes.