To ensure a strong defence in Yoruba Pre-Colonial Political System, the Are-Ona-Kakanfo was assisted by the

Analyze the question: The question asks about defence in the Oyo (Yoruba) pre-colonial political system. The Are-Ona-Kakanfo was the commander-in-chief of the Oyo army. We need the group or officials who assisted him in keeping the empire's defence strong.

Explain the concept:

• Are-Ona-Kakanfo: Field marshal of the Oyo Empire. He commanded the army and was usually stationed in a provincial city (Ilorin) away from the capital, so he could not easily stage a coup against the Alaafin.
• Eso (Eso Ikoyi): The 70 military chiefs/captains of the Oyo army, nominated by the Oyo Mesi and appointed by the Alaafin. They were the elite military officers who assisted the Are-Ona-Kakanfo in commanding troops and defending the empire. The head of the Eso was the Aare Ago.

Check the options:

• A. Aremo: The Alaafin's eldest son and heir-apparent, not a military assistant.
• B. Balogun: A war chief in many Yoruba towns. In Oyo, it is a military title, but in this question the group that formally assisted the Are-Ona-Kakanfo in the Oyo system was the Eso.
• C. Chief priest: A religious functionary (e.g., the Bashorun also handled Ifa and Sango rites), not military.
• D. Eso: The body of military chiefs who assisted the Are-Ona-Kakanfo in defence.
• E. Oloja: Means "owner of the market", a market title, so it is not relevant.

Answer: D.

Tip: Remember the Oyo structure this way:

• Oyo Mesi = civil/legislative council (led by the Bashorun)
• Eso = military chiefs (under the Are-Ona-Kakanfo)
• Ogboni = religious/judicial cult

"Eso = Soldiers" is a quick link for exams.