The aim of this article is to assess the expansion of Oromo population in Ethiopia in general and Salale region in particular. Long before 1991, the history and culture of Oromo was not correctly studied. The main reason for this is the fact that the Oromo were politically submerged and marginalized in historical studies. The Abyssinian writer Abba Bahrey attached the wrong view and regarded the Oromo as warriors or invaders. Donald N. Levine supported the view of Bahrey the Oromo as warriors. From the Tesema Ta’a reference, the earliest historical writing on the movement of Mecha and Tulama was the work of Abba Bahrey in the 16th century. According to this source Bahrey did not mention Oromo as foreigners but Bahery regarded their moment as the whole Oromo gathering force overwhelming at once time. Also, the Oromo scholars like Mohammed Hassen and Asafa Jalata seem to have accepted the thought that the Oromo of Tulama and Macha used to naturalize non-Oromo people by force. Different scholars supposed a hypothetical description about the early inhabitants in the Salale area before the 16th century and from where the Oromo began their expansion and penetrated to the anterior parts of Salale region. Among those people that were forced to accept Christianity and baptized were the Galan and Yayya Oromo. Before they were forced to accept Christianity the people of the Galan and Yayya were used to worship the God called Qorke.

Keywords: Abba, Gada, Macha, Tulama, Qorke, Atse, Afaan, Fitwarary, Neftagna