During the height of the Atlantic slave trade (17th–19th centuries), the Aro Confederacy (c. 1690–1902), centred on Arochukwu, built a commercial, religious and military network across the hinterland of the Bight of Biafra. The Aro called themselves Umu Chukwu, “Children of the High God”.
Their power rested on the Ibini Ukpabi, the oracle the British named the “Long Juju”, in a cave complex with a stream and a “throne of judgment”. Because decentralized Igbo communities had no central court of appeal, the oracle served as supreme judge in cases of land, murder and witchcraft. Verdicts were final: the innocent were acquitted, while the guilty were said to be “devoured”.
Historians have shown that many of those condemned were in fact smuggled out and sold to European buyers at ports such as Bonny, Onitsha, Abonnema and Oguta. When judicial verdicts did not provide enough captives, the Aro allied with mercenary warriors from Abam, Ohafia and Edda communities, who raided on their behalf. Scholars still discuss the exact scale, but the system created deep insecurity across the hinterland.