The BAJA PEOPLE OF THE NILE

According to Strabo(63BC-23AD),  the Baja were a Black-skinned people who were used to raiding and pillaging on the fringes of the desert.... "The Baja, were a people around the Nile in Egypt and the Sudan, fond of daggers, swords, scimitars and camels; their hair was made curly by a hot knife" (instead of weaving the hair, like the male Luwata and Gatuleg).They 'were as black as tar' and weren't "good to have as a friend or foe".

These were among some of the ancient tribes that made up what was most of north Africa before the coming of the Persians, the Assyrians (during the reign of Ashur banipal), the Greeks, the Romans, the Hyksos and the coming of the Caucasoid groups known today as the Arabs in the 3rd century CE, a situation that intensified in the 7th and 8th century CE with the spread of Islam and Arab slave trade as well as the trans-saharan trade.

The effects of concubinage, Barbary slavery, migration and earlier encroachments of Europeans into Africa, especially, contributed greatly in altering the population of the northern parts of Africa. For example, Mulai Ismael of Merknes, brought into north Africa 25,000 European slaves who participated in the building of his colossal stables.

These groups later became the dominant groups in north Africa after the fall of the African Maghrebs in Iberia and Africans lost control of trade routes in the Mediterranean in 1492 CE, as well as the resultant effects of the Turks takeover of Constantinople and later the whole of Byzantium. During the peak era of the Arab slave trade, the Muslims often received European women as homage from traders and caliphs in Granada, Cordova etc, which were brought into north Africa and the Arabian peninsula. 

The African male of the Soudan who  fall under the burden of the slave trade were castrated to avoid procreation. These groups were fewer in number than the enslaved Europeans in north Africa before the 15th century CE, but the focus on mostly Black-skinned people began in the later parts of the 15th century CE, as Europe became more organized along national lines and could shift the tides of slavery.