As is now generally accepted, early tenth century anno domino, witnessed the fusion of three dynasties in the south eastern zone of Nigeria, into the nation state Aro. There was the Ibibio clan of Obong Okon Ita dynasty with its seat of government in Obot Okon Ita. The other two contingent dynasties, located north and north-east of this Ibibio territory were the Igbo dynasty of Mazi Agwu Inobia, a blacksmith with his seat of government in Akanu Amanagwu, and the Igbo dynasty of Mazi Nnachi Ipia, a traditional medicine man with his seat of government in Utughugwu.
The need for peaceful co-existence between the Ibibio tribes at this border reign, led to the marriage alliance of Obong Okon Ita dynasty with that of Mazi Agwu Inobia. But subsequent territorial ambitions by the Igbo dynasties, dictated the need at the passing away of Obong Okon Ita, to prompt and support Ulu AKakpokpo Okon, the ulu [second son] of Obong Okon Ita by the marriage to an Igbo lady, to succeed to the Obongship in place of his elder brother Akpan Okon.
The Coup d'etat which was very much resisted led to a protracted and unprecedented conflict in the region that it required the engagement of a mercenary force of Akpa Warriors from across the lower Cross River Area located north of Akamkpa, South of Ogoja and West of Obubra. This mercenary army was contracted by Mazi Nnachi Ipia. When the war ended in favour of Ulu Okon, by some queer coincidence, he himself and Osim, the leader of the Akpa Warriors, were among the causalities. This double loss of leadership by the two non-Igbo parties in the war effort was very much suspect and the conflict was to have led to a feudal strife.
In a compromised solution to this conflict, Osim's lieutenant, Akuma Nnubi was offered the primacy and suzerainty of the emergent confederacy which was later to be called Arochukwu. The mercenary army then settled for good in Ibom Oburutu [Ibom Etiti]. The Ulu Okon dynasty naturally fussed by cultural matrilineal kinship with Mazi Agwu Inobia dynasty where it retained its erstwhile primacy.
The resultant confederacy therefore, consisted of three independent and autonomous dynasties but was nevertheless collectively labeled by the sacked Ibibios as Ulu Okon dynasty, and is to this day known in its corrupted form of Inokon by the Ibibios and Efiks. Parallel corruption of the name, Ulu among the other Igbo tribes, later crystallized into the name Aro. The adjectival suffice “Chukwu” was later added when the worship at the Ibit Itam shrine dedicated to the deity of Obong Okon Ita dynasty was popularized among, and became extensively influential within the Igbo tribes as an omniscient oracle and omnipotent deity.
Necessary political adjustments within the confederacy, called to transference of primacy from the Akuma Nnubi dynasty to that principal who recruited the mercenary army in the first instance, namely Nnachi Ipia dynasty. Consequently, the primacy of dynasties within the Aro confederacy has reposed with the lineage of Nnachi Ipia, not in absolute terms, but in the uniquely triumvirate model of a republican confederacy.
Each of the dynasties [now labeled clans] expanded into various city states, currently labeled Ogo [now loosely called village]. Each Ogo was in turn composed of several Ezi, [loosely called family or compound]. A pyramidal structure of Ezeship, stretches from the clan down to the compound. As each ezi has an Eze, so does each Ogo, and each clan. This leaves a triumvirate at the top of which one is the primate though not in an absolute sense. We are all conversant with the stereotype English expression of our fathers in inter pares [first among equals]. The term Aequals does not though include the Eze-ogo and definitely not the Eze-ezi, but the Eze of the root of Nnachi Ipia; the Eze Eze Agwu of Ulu lineage, and Eze Ibom Isii of Osim/Akuma Nnubi lineage.
This city state [Ogo] had autonomy of governance and the emergence and growth of the Aro Empire was due to the independent expeditionary trade and foreign relations of their individual influential merchants. The situation was very much the same as in the birth, composition and growth of some other well documented empires such as that of Rome and Greece. Unlike the British Empire, no Aro expeditionary merchant [Okoroji or Izuogu for instance] ever took control of a territory in the name of the King. Whatever was done by the individual or the city state was done for his or its own interest, but without prejudice to or compromise of the welfare of Aro commonwealth. This explains why Aro Empire and governance has always been and always will be that of republican confederacy and why a unitary governance of administration is an inconceivable anathema to the Aroman.