According to the traditional account at the demise of Oba Eweka I, two of his sons Idu and Uwakhuanhen became rival claimants to the throne of Benin. Prince Idu the eldest son whose mother hailed from Umoghumwun was not favoured by the elders who then back younger brother. As a means of getting rid of Prince Idu, the elders brought a plan which requested the rival princes to provide a cow with bird’s nest built upon its head for the purpose of their father’s royal funeral ceremonies prince Idu was then persuaded to go to his mother’s home town Umoghumwun to procure the proverbial nested cow. His rival brother then remained in Benin where a cow was procured and a bird’s nest planted upon its horn. The cow was then presented before the elders who immediately declared Uwakhuanhen successor to the throne. He was then crowned Oba. With Uwakhuanhen on the throne, war became imminent between the two brothers. To appease Idu, the kingdom was divided. The southernmost point or boundary of Prince Idu’s kingdom was some seven kilometres (Umaguohen) from the North East of Benin City. His southernmost limits terminated at the Ethiope River while the northern extent was the River Orhionmwon (‘Ossiomo” as the European mispronounced the name). Idu styled himself Oba N’Ugu (Oba of Ugu) and he then established his headquarters at Umoghumwun. This kingdom included the whole of the present Urhonigbe and Ugboko districts; as a matter of fact, the whole of the area now known as Iyekorhionmwon. Over the ensuing years, the kingdom of Ugu rivalled Benin. By the reign of Oba Ewuare the kingdom of Ugu was ruled over by Prince Alegbe as Oba N’Ugu who held such sway in the kingdom that he practically created nearly all the Enigie in the area in the same manner as the Oba of Benin did in the rest of Benin Kingdom. Among such Enigie created by Oba N’Ugu were Enogie of Evboesi, Enogie of Oben and Enogie of Ebazogbe N’Ugu and Ikobi. The expansion of the Oba of Benin’s powers into these territories began in the reign of Oba Ewuare the Great (circa 1440-1473) who invaded the area from the north-west which brought Oheze, Eso and Ugheka village groups under his temporary control. It is said that the successors to Ewuare could not maintain the positions although Oba Ozolua (circa 1483-1504) was able to destroy Ogba which was one of Alegbe’s outposts, from where he gained control of Iguelaba and thereafter settled a Benin garrison at, Ologbo (in Iyekorhionmwon area). Oba Esigie (circa 1504-1550) who succeeded Oba Ozolua, extended his control southwards by founding Igbekhue while Oba Orhoghua (Oba Esigie’s son, circa 1550-1578 A.D.) founded Idu and Iguosia.

Oba Ehengbuda over-run Ugboko N’Iro and advance on Ugo where he established Agboghidi as Enogie to keep the people of Ugu and the war like Iyokorhionmwon from attacking Benin. It was from the Ugo headquarters that Oba Ehenbuda sacked Umoghumwun and thereafter settling a group of executioners at Urhehue to destroy the remnants of the followers of Oba N’Ugu whose name was at that time, Ogiewon. It is said that Ogiewon fled to Ishan area. The story about Ogiewon went like this when his father wanted a child to succeed him he consulted an oracle which prescribed a hen to be used as sacrifice. Oba N’Ugu then requested one of his wives to offer her hen for the sacrifice. This wife refused but another wife then offered a hen for the sacrifice. In the end, the two wives each gave birth to a boy. The elder son named Ogiewon belonged to the wife who refused to submit her hen for sacrifice while the younger son named Alegbe belonged to the faithful and generous wife whose hen was eventually used for the sacrifice. Oba N’Ugu then blessed the second son. As a further mark of favour, Oba N’Ugu left a sizeable portion of his wealth and regalia to the second son. At the demise of Oba N’Ugu, Ogiewon (the senior son) succeeded to the Ugu throne and it happened that it was at that time Oba Ehengbuda sacked Umohumwun and Ogiewon fled to Ishan land. In Ogiewon’s absence, his brother Alegbe, the second son of Oba N’Ugu who had his father’s blessings, was made Oba N’Ugu and he reigned over Umoghumwun now known as Umoghumwun N’Okhua. Subsequently Ogiewon eventually made peace with the Oba of Benin, and was allowed to return to Ugu where he founded the village of Umoghumwun N’Uzuagbo. This situation explains why the Enogie of Umoghumwun N’Uzuagbo is admittedly the senior in the sense that he was first to be made Enogie though Enogie of Umoghumwun N’Okhua came out to be more powerful in the area.

The following are the nine villages which claim to be direct descendants of Oba N’Ugu:
(i) Umoghumwun N’Ekhua
(¡i) Umoghumwun N’Uzuagbo
(iii) Ogba
(¡v) Evboesi
(V) Oben
(vi) Ebazogbe N’Ugu
(vii) Ikobi
viii) Urhehue
(ix) Ologbo

The following are hereditary titles in the Ugu area:
(1) Enogie of Umoghumwun N’Okhua
(2) Enogie of Umoghumwun N’lizuagbo
(3) Enogie of Evboesi
(4) Enogie of Oben
(5) Enogie of Ebazogbe N’Ugu

It is interesting to note that the Enigie created by Oba N’Ugu were recognised by subsequent Obas who brought the area under the control of Benin, while Oba N’Ugu’s brother who took over the throne of the kingdom when it was overrun was eventually recognised as Enogie by the Oba of Benin. He was also confined to his village and no more recognised as the Oba N’Ugu.