Oromo are the largest ethnolinguistic group of EthiopiaCorey Barksdale Graphics

Oromo, the largest ethnolinguistic group of Ethiopia, constituting more than one-third of the population and speaking a language of the Cushitic branch of the Afro-Asiatic family. Originally confined to the southeast of the country, the Oromo migrated in waves of invasions in the 16th century CE. They occupied all of southern Ethiopia, with some settling along the Tana River in Kenya; most of the central and western Ethiopian provinces, including the southern parts of the Amhara region; and, farther north, the Welo and Tigre regions near Eritrea. Wherever the Oromo settled in those physically disparate areas, they assimilated local customs and intermarried to such an extent that much of their original cultural cohesiveness was lost. They were eventually subjugated by the Amhara, the next largest ethnolinguistic group in Ethiopia.