The rain forest zone is inhabited by some of the oldest surviving ethnic groups in Nigeria. The thick natural vegetation of this zone offers protection to these groups against their enemies. The largest known ethnic groups in this zone include the Yoruba and the Edo of the southwestern part of Nigeria and the Igbo, Ibibio and Ekoi of the south east of Nigeria. The Yoruba speaking peoples of Nigeria occupy the western states of Oyo, Lagos, Ondo, Osun, Kwara states.
They are marked by linguistic homogeneity and have a common tradition of origin that has been traced to Oduduwa, believed to have established the Ife dynasty. The Yoruba recognized two important institutions and their occupiers. The first is the Oni of Ife, who is considered the spiritual ruler of all Yoruba, while the second is the Alaafin of Oyo, who is considered the political head of the Yoruba people.
Another significant feature of this ethnic group is their settlement patterns. Although a predominantly agricultural people, the Yoruba have an age long tradition of living in towns, the largest of which include, Ibadan, Oshogbo, Ilorin etc. It has been observed that the Yoruba are the most urbanized group not only in Nigeria but also throughout the African continent. The evolution of this pattern of settlement among the Yoruba has been associated with several factors. Some scholars have emphasize the need for defense while other associated it with the highly centralized nature of the political organization of the people.
For others however, it may have emerged from the diversities of the people's economic activities during the Pre-colonial period. Whatever was the true situation of things may have been the urbanized style of settlement facilitated and strengthen the growth of trading and commercial activities among the Yoruba on the one hand and between them and their immediate neighbours, especially the Nupe and Hausa ethnic groups. The basic unit of social organization among the people is the family usually headed by the elderly people. The primary occupation of the people is farming, mainly engaged in by men, while the women were primarily traders. The Yoruba are also noted as very good artisans and craftsmen, excelling in wood carving, bronze heads of Ife, reported to be about 800 years old is a demonstration of the high quality of traditional Yoruba craftsmanship. The Yoruba people are very religious and are known for their respect for constituted authorities and elderly people. A particularly peaceful people, the Yoruba have a very rich culture expressed in the nature and character of their political and social institutions and their material production.
The Edo speaking people occupy the territory situated in the east of Yoruba land and are popular for their powerful kingdom and empire of Benin. They have several traditional links with Yoruba with whom they also share the same political system. The Edo political system was based on the state in which the focus of political and cultural activities revolved round Benin city, the seat of power during the pre-colonial times.
At the apogee of its power in the 15th century, Benin influence was felt far and wide, extending from the banks of the lower Niger valley to the Republic of Benin. During this period, the Benin empire merits the description of a loose kingdom since it embraced a large number of ethnic groups. In addition to Edo, other ethnic groups who fell under the influence of the Benin kingdom included the western Igbo and other Yoruba groups. The Igbo towns scattered on the east bank of the lower Niger like Onitsha, Atani and Ossornari were known to have been founded by migrants from Benin. Like their Yoruba neighbors, the Edo speaking people were also famous for their wood work, metal work and bronze casting. They were also very significant traders in Pre-colonial Nigeria, exchanging wares they locally produced for those they could not produce. Benin beads, for instance we're very popular in the whole of southern Nigeria and in parts of the Middle belt where they were considered as prized ornaments.
The Igbo and Ibibio ethnic groups inhabit the south east of the rain forest zone. Each of these two groups is divided into several sub-groups. History has it that none of them ever evolved a large state or kingdom similar to those of the Yoruba and Edo. Among these people, the largest political unit was the village group authority which usually had population of only a few thousand people. Even at the village level, authority was never concentrated in the hands of any individual and there were no chiefs. There was also no ruling aristocracy, which wielded authority as a specialized full time occupation. Instead, what prevailed in these societies was the authority of Elders constituted in a council.
Like their Yoruba and Edo counterparts in the south west, the Igbo and Ibibio were predominantly agriculturists. The people lived mostly in the villages. Thus their settlement pattern was different from the Yoruba and Edo people. In this connection, urbanization among these groups is a colonial phenomenon. The history of the zone cannot be complete without a word or two on the Aro Igbo of Arochukwu. Arising largely from their mythical powers, the Aro came to be respected and feared as the children of God throughout the southern zone and parts of the Middle Belt. It was this privilege that made them very popular and influential in Pre-colonial Nigeria just as it helped them to play a leading role in organizing and controlling the flow slaves in parts of the southeastern Nigeria.