HOW DID ISLAM CONQUER AFRICA? DID CHRISTIANS FIGHT BACK?

According to the General History of Africa, Vol 3: Africa from the Seventh to the Eleventh Century, there were several basic patterns of Islamization in Africa between the 600 and 1000 C.E (A.D.)

1) The Arab conquest of Egypt and North Africa
2) The commercial activities of Muslims
3) Clerics and holy men spread the word
4) The penetration into different societies into Arab societies 

 From: http://17-122.qataracademy.wikispaces.net/Islamic+Empires+Webpage

From: General History of Africa, Vol 3: Africa from the Seventh to the Eleventh Century, pages 90-91

"Christians fought back as much as they could, however. In North Africa, in Nubia and in Ethiopia the incoming Muslims encountered Christianity. The resistance of local Christians to Islamization varied according to local political and social conditions. In the Maghrib where the Christians represented only a minority (mostly of mixed or foreign origin), Islamization has been more complete and Christianity completely  died out by the eleventh century. In Egypt the process took a longer time being accelerated only by the Fatimids; Islamization has never been complete, as about 10 per cent of Egyptians still belong to the Coptic Church. 

In Christian Nubia, by contrast, the impact of Islam until the end of the thirteen century was minimal but during the next two centuries Christianity gradually vanished, being superseded by Islam. Only in the Ethiopian highlands were Christians able to resist. Neither the peaceful penetration of Muslim merchants nor the military campaigns of Muslim states to the south of the plateau shattered the fidelity of the Ethiopians to the faith of their fathers. Although Christianity in Ethiopia emerged from this centuries-old struggle victorious, it remained an isolated outpost amidst a Muslim sea."