Royal Caste: Imperical structure

Matriarchal society, Queen rules with or without the aid of her consort(s), as she chooses. Law decrees that a queen may only rule until her heir comes of age. If no heir is produced within ten summers the high priestess will choose one from the royal caste. This heir is usually, but not always, from a different house than the current queen since infertility is the highest sign of dishonor Jyӯ can curse a woman with.
First Daughter-Heir, when she comes of age at twenty summers, chooses a consort from the royal caste and ascends the throne. When a new Queen takes the throne she chooses a female child no more than twelve and no less than five summers old from the religious cast to become High Priestess when her own heir ascends the throne, This allows the young (and theoretically virginal) queen to always have an older and more experienced adviser. The new queen also chooses a child of seven who is of the warrior cast to train under the First Commander during her reign, that child takes the position of First Commander when the next queen is crowned. Once these decisions are made the queen must have the approval of the High Priestess (and thus the gods) to change them. To show the unity of the ruling cast with the warrior and religious cast the queen's siblings are wed by birth order regardless of gender.
First to the High priestess
Second to the First Commander
Third to the First Commander's Brother
If the queen has no siblings those in these positions will remain unwed.
There are nine houses in the royal caste, Each has a patron deity, each rule over one city/region in the kingdom under the queen's command, the woman carries the house name, a man may only marry once but a woman may marry as often as she likes, the queen has absolute power but has a counsel of advisers, the matriarch of each house being both governor and delegate to the royal counsel, the governors are not subject to the same replacement laws as the queen