“To the south of a zigzag boundary which stretches from Fernando Pó on the west to Mombasa on the east, lies the sphere of the Bantu speech. … There is but one indigenous language-family over the whole of Central and South Africa, the only exceptions to this universality of type being a few patches of Sudanian tongues on the Northern Congo, Nilotic dialects in East Africa, a click language south of the Victoria Nyanza, and the nearly extinct Hottentot and Bushman languages of South-West Africa” (Johnston, Sir H. H.: The Opening Up of Africa (London, no date, Williams & Norgate), pp. 131-2).
Swahili is a Bantu language and, of course, is spoken in Kenya north of Mombasa. Afro-Asiatic, once called Hamito-Semitic, must be a rather loose group. The Hottentot and Bushman languages are also Khoisan or click languages.
Parts of West Africa and the Sudan are extremely linguistically diverse. Nigeria has 522 living languages (Ethnologue, 358 classed as “vigorous”), one of the greatest concentrations of languages in the world. Bantu languages are themselves diverse.
A Study of History, Vol III, OUP, 1934