What is one thing that most if not all African kingdoms had in common?

Most African kingdoms became rich from cloth.

Most African kingdoms practiced slavery.

Most African kingdoms practiced Islam.

Most kingdoms fell, showing the movement from stateless to state societies can be difficult.

One thing that most if not all African kingdoms had in common is that they were organized around a centralized authority, often led by a king or queen, and had a hierarchical structure of government with defined territories and administrative systems.