The monarchy of any city state was usually limited to a number of royal lineages. A family could be excluded from kingship and chieftancy if any family member, servant, or slave belonging to the family committed a crime such as theft, fraud, murder or rape.
In other city-states, the monarchy was open to the election of any free-born male citizen. There are also, in Ilesa, Ondo, and other Yoruba communities, several traditions of female Ọbas, though these were comparatively rare.
The kings were traditionally almost always polygamous and often married royal family members from other domains.
Ibadan, a city-state and proto-empire founded in the 18th century by a polyglot group of refugees, soldiers, and itinerant traders from Ọyọ and the other Yoruba sub-groups, largely dispensed with the concept of monarchism, preferring to elect both military and civil councils from a pool of eminent citizens. The city became a military republic, with distinguished soldiers wielding political powers through their election by popular acclaim and the respect of their peers. Similar practices were adopted by the jẹsa and other groups, which saw a corresponding rise in the social influence of military adventurers and successful entrepreneurs.