As illustration only, some african people in the lands of islam.
al-Sahib ibn Abbad: Al Tadhkira fi ‘l-Usul al-Khamsa;
(To Remember the five Principals) (d995) (Iran; Wazir from the Buyids)
-------------------------------------------------------------------------------Taken from : Charles Lindholm : The middle east: Tradition and Change.
Sahib Ibn Abbad: al-Muhit fi al-lughah (Ocean in the language) (995)
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Taken from: alwaraq.net
Dgaop (1): race of the Sudan behind Zinj
Alkharzinjy (2): A Tale of Al Jahiz in which: Zinj of two kinds, one called lkfw and the other lytw
Zeng: Zinj and Zinj: blacks, and perhaps say: Znag (when calling someone). And Almzenjh: group of Zinj. The tender Mzenj: little.
And Almzenj: small zenj.
(1) Dgo: Dgaop; This he repeated from: Al-Khalil ibn Ahmad al-Farahidi. Kitab al-'Ayn (The source) (d791). Maybe the Daghuta of Idrisi (1150). Which is also found in Ibn Manzur (1290); Ibn Sida (1066) Qadi Ibn Sasri Al-Shafi’I (1300); Abulfida (1331); Ibn Said (1250); Al-Dimashqi (1325); Al Himyari (1461) has Daghwata. In idrisi (1150) it is the furthest south town in the land of Sofala. Sofala was one of the earliest places to be visited by Muslim traders for its gold; together with Qanbalu (Pemba) for its slaves.
(2) Alkharzinjy: A Tale of Al Jahiz in which: Zinj of two kinds, one called lkfw and the other lytw
-Jahiz (869) repeated it in two books: Kitab al Hayawan and Al-Fakhar al-Sudan: The tribes of Zinj are of two types: the ants and the dogs, this tribe are the dogs, and that tribe are the ants.
-Al-Dimashqi (1325): they are divided in two tribes, the Qabliet and the Kendjewiat, the first name means ants, the second dogs.
-Suyuti (1505): As for Zinj, two classes Kabila and Katajwia.