The Igala mega state attained the height of its fame during the mid-17th century. The rise of the Igala mega state disrupted and contributed to the shift of the Trans-Atlantic slave trade from the Bight of Bini the decline of the Bini Empire between the sixteenth and seventeenth centuries. The Idah-Bini war (1515–1516) was a war of mutual independence. The Igala state reached its political and commercial supremacy afterwards, when it became a leading exporter of choral beads, horses, medicine, skills and of course, slaves to the coastal region. Its growing power, nevertheless, changed the dynamics of the earlier complex relationships with several northern Igbo communities.
Joseph Hawkins in 1797 already captured the relentless raiding of the extreme northern Igboland by the Igalas. In his "A History of a Voyage to the Coast of Africa" he noted the growing conflicts between the "Ebo Country" and "Galla". By the late 17th century, the Igalas conquered and held socio-economic, political and religious control of the northern Ibo mini-states. From Opi (archaeological site) , Nsụka , Nsugbe, several Ibo communities on the [[Ọmambara River ]], the lower Niger, through Okpanam to Ahaba the Igala held sway. Trading out post with Ọnicha and the Ijọ middlemen were fully established. The mythical Omeppa, Inenyi Ogugu set up garrison at Opi (archaeological site) and several Igala warlords played their part in the buildup of the Igala colonial take over of these northern Igbo states. But no other individual played a greater role in shaping Igala-Igbo colonisation during the 18th century than Onoja Oboni, the legendary Igala warrior and slave trader. Onoja Oboni's personality and heritage has been shrouded in mythical imagery over time. Ranging from being the Son of Eri, the grandson of Aganapoje to being a descendant of one of the Idah royal families; the priestly sub-clan of Obajeadaka in Okete-ochai-attah.
By Kabir Amodu