Historical linguistics and comparative ethnology studies suggest that the Oromo people probably originated around the lakes Lake Chew Bahir and Lake Chamo. They are a Cushitic people who have inhabited the East and Northeast Africa since at least the early 1st millennium. The aftermath of the sixteenth century Ethiopian–Adal war led to Oromos to move to the north. The Harla were assimilated by the Oromo in Ethiopia. While Oromo people have lived in the region for a long time, the ethnic mixture of peoples who have lived here is unclear. The Oromos increased their numbers through Oromization ("Meedhicca", "Mogasa" and "Gudifacha"), assimilation, and forced assimilation of other ethnic groups, as well as the inclusion of mixed peoples ("Gabbaro"). The native ancient names of the territories were replaced by the name of the Oromo clans who conquered it while the people were made Gabbaros.