The main Objective of this study is to unearth the history of the lineage of the Oromo of Gumma kingdom. In this study the research employed both the primary (oral sources mainly) and secondary sources and different data gathering instruments. The result shows that, the Oromo of Gumma, during their expansion into the present areas the area was inhabited by the pre-Oromo communities, Kaffa and Ennarya were the most known. The settlement pattern of the Oromo of Gumma was the earlier one to be settled in the Gibe region. Again, there were different tribes, clans and sub-clans of Maccaa inhabited in Gumma. Adami and Dagoye are among the major tribes and the remaining are sub and sub-sub clans of Maccaa. Their expansion brought about a cultural assimilation of these different non-Oromo ethnic groups and also expulsion of some pre-Oromo communities. Gumma Oromo have occupied the whole fertile and suitable highland areas. Keywords:Genealogy, Gumma kingdom, pre-Oromo inhabited and assimilation DOI: 10.7176/RHSS/12-13-01 Publication date:July 31st 202
