This site brings you the history of the Islamic Jihad from its beginnings at Mecca in 620 C.E. up to 9/11, and the lessons it has for us in today's challenging times. If we are to understand Islam, we need to understand the temperament of its founder Mohammed (PBUH*), the way victorious Muslims have treated the subject people, and above all the reasons for the victory of Islam.
Central Africa was a poor semi-arid land with scrub vegetation, and there was nothing therein worth fighting for and holding the land and population under Muslim tyranny. As there were no major cities worth the name, and most of the population lived in migratory groups as hunter, food gatherers and cattle herders, there was precious little to tempt the invading Muslims by way of booty. Hence there was no sustained Muslim invasion of Africa proper. Muslim raids were confined to the Mediterranean coastline in the North and along the Nile Valley in Egypt.
This also speaks the mind of the Muslims to raid non-Muslim lands not only for spreading Islam but to loot, plunder, rape. In the absence of any significant wealth, the lands were not subject to occupation, although there were continuing raids through the millennium from the 7th up to the 18th centuries. But during these raids the aggressors did use force to compel the African (Bantu, Bushmen, Masai and other Negro clans), to join the Muslim Ummah, by embracing Islam at the point of the sword as commanded by the Quran.
This difference was because the Muslims could not hold the converted African tribal populations to Islam, due to the victims being migratory in their utterly frugal and substance based lifestyle
Migratory Tribal populations living at sustenance levels dissuaded the Muslims from concentrating on Africa up to the 18th century.When the Jihadis attacked Central Africa, South Central Africa, up to the Atlantic shore in Ghana, the people of that region were divided in to independent tribes. Each tribe worshipped its own tribal god. Witchcraft and Shamanism were prevalent. Many of the tribes were engaged in internecine warfare for cattle, control over grazing pastures and hunting grounds. There was no unity among the tribes. And till the Mameluke led Muslim invasion, no invader had ever penetrated in to the heartland of Africa.