30+ Burial Customs for building cultures
The Yughort were the fathers of the steppe civilizations, rulers of the first nomadic empire of the plains. Their signs can still be found, including their conical burial towers.
A kingdom where, if there are multiple princes (princesses can't rule unless they have no siblings), the princes fight to the death in the arena to decide who gets to rule. A simple way to make sure your brother cannot make a bid for the thrown, and keeps the royal blood in one line.