Prehistory
The African peoples who lived in Yorubaland, at least by the seventh century BC, were not initially known as the Yoruba, although they shared a common ethnicity and language group. The historical Yoruba develop in situ, out of earlier (Mesolithic) Volta-Niger populations, by the 1st millennium BC.
Oral history recorded under the Oyo Empire derives the Yoruba as an ethnic group from the population of the older kingdom of Ile-Ife (see also Yoruba mythology). Archaeologically, the settlement at Ife can be dated to the 4th century BC, with urban structures appearing in the 12th century (the urban phase of Ife before the rise of Oyo, ca. 1100-1600, is sometimes described as a "golden age" of Ife).
Read more about this topic: Yoruba History