Thanks for the question.
I posted that quotation from Egharevba’s book as a follow up to a piece I posted a few days ago regarding the fact that there were two (2) female Ogisos during the first period but no female Oba during the second and third periods (so far). It would seem that Egharevba has answered your first question. The enactment was made in the late 15th century at a time of rapid transition.
After Ewuare the Great broke chalk, his eldest son Ezoti succeeded him. If you recall Olua (Edeleyo’s younger brother) succeeded Ezoti (circa 1473) who himself moved on to the great beyond within 14 days – shot by an aggrieved palace boy during coronation.
According to Egharevba, when Ezoti began his journey to the spirit world, his brother Okpame went to Esi to bring Ezoti’s only son (Owere) back to take the throne. Sadly, Owere and his mum were assassinated on the way back (buried alive) by Okpame – but news of his action leaked leading to his banishment (exile) to Ora.
Fear of Okpame made Olua (Ewuare’s second son) initially refuse the throne. Thus, Edeleyo (Olua’s older sister) was invited to become Oba. She was actually installed as Edaiken but fell ill to an unspecified incurable female complaint on her way to Uselu. The spot where she took ill is called Ogbe Edeleyo and bears a shrine to this day. Every Edaiken since then has been decreed to offer a sacrifice at this spot on his way to Uselu.
Back to Edeleyo. Seeing as her problem was incurable and of a peculiarly female nature (do not ask me what) the Uzama and Eghaevbo enacted that no woman should be allowed to reign in the future. They subsequently prevailed upon Olua to take the throne – which he did. (NB: Olua was Prince Iginua’s father. Iginua is the founder of Itsekiri. The title “Olu” of Itsekiri comes from the word “Olua”.)
The women who would ordinarily claim the throne would be first borns. I do not know how Edo women feel about this 500 year old custom. It would seem, however, that it is theoretically within the power of the Uzama and the Eghaevbo (supported by sacrifices to Edeleyo and mindful of modern gynecological care) to rescind the edict promulgated in the 15th century which to this day prevents women from ascending the throne. But do not expect such an action anytime soon. The men (led by Hilary) are watching. Ours (like many others) is an alpha male primogeniture culture – rightly or wrongly.