The first language to separate seems to have been Omotic, at a date sometime after 13,000 B.C. Omotic speakers moved southward into the central and southwestern highlands of Ethiopia, followed at some subsequent time by Cushitic speakers, who settled in territories in the northern Horn of Africa, including the northern highlands of Ethiopia. The last language to separate was Semitic, which split from Berber and ancient Egyptian, two other Afro-Asiatic languages, and migrated eastward into far southwestern Asia.
By about 7000 B.C. at the latest, linguistic evidence indicates that both Cushitic speakers and Omotic speakers were present in Ethiopia. Linguistic diversification within each group thereafter gave rise to a large number of new languages. In the case of Cushitic, these include Agew in the central and northern highlands and, in regions to the east and southeast, Saho, Afar, Somali, Sidamo, and Oromo, all spoken by peoples who would play major roles in the subsequent history of the region. Omotic also spawned a large number of languages, Welamo (often called Wolayta) and Gemu-Gofa being among the most widely spoken of them, but Omotic speakers would remain outside the main zone of ethnic interaction in Ethiopia until the late nineteenth century.