The original note, as written at the time
A pastoral East African empire whose rulers are bound to a special breed of cattle that can transform into various combat forms that can defend their masters.
Ongoing development
The first thing you must understand about the cattle is that they are not animals that fight for you. They are animals you are responsible for.
Every house of the empire is bound to a herd, and the bond is not ownership. You cannot sell a bound beast and you cannot eat one, though both have been tried. What you can do is keep it well, and what it gives you in return is a form in which it will stand between you and the thing that is coming.
It changes shape, but the change is not the point, because the change only lasts as long as the animal is not exhausted. A beast that has been worked too hard in the field cannot take a combat form at all; it will try, and you will watch it fail, and the failure is a humiliation the household carries for years. So the household that fights best is not the household with the strongest beasts. It is the household with the feed.
My grandfather was a good herdsman and a poor soldier and he died old and rich, which in that country was considered a scandal and then, later, considered wisdom.
The politics follows the feed. The houses that own the grazing routes have more bound cattle than the houses that own the towns, and the towns have never forgiven that. When the emperor’s envoy came to my father asking how many beasts the family could raise, my father said six, and the true number was nineteen, and the envoy knew the true number was nineteen, and both of them enjoyed the exchange because it was the only kind of war either side could afford that season.
What the empire has never resolved is what happens when a bound beast outlives its house. It cannot be sold, so it must be kept, and it will accept no other hand. Three of my grandfather’s are still standing in the south field, forty years after the last of his sons died, and they will not be fed by anyone but the family, and the family is now me, and I sell none of them, and every year the grazing costs me more than the land is worth.
That is the whole of the bond, and nobody warns you. The cattle defend you, and then they outlast you, and then they become the only thing in the world you are still obliged to.