A king is born, not made. The first son of a reigning king is automatically born a king. Otherwise is pure politics. Oba of Benin is the direct son of oronmiyan direct son of Oduduwa direct son of the last Ogiso (owodo) of igodomigodo kingdom. yorubas may get it twisted for political reasons but I bet you, the secret spiritual men of Ife knows the traditional truth. Most kings in yoruba land bears Edo original strong names. Anyway, there is nothing like yoruba, it is just a political name created for political reasons just like ibo and hausa groups. We are all original igodomigodos occupying the today southern nigeria and the Republic of Benin and up to ghana with common ancestors.