How did Islam and the spread of
that religion impact the slave
trade?

Maybe Iran or Jerusalem?

Islam had already spread into northern Africa by the mid-seventh century A.D., only a few decades after the prophet Muhammad moved with his followers from Mecca to Medina on the neighboring Arabian Peninsula (622 A.D./1 A.H.). The Arab conquest of Spain and the push of Arab armies as far as the Indus River culminated in an empire that stretched over three continents, a mere hundred years after the Prophet’s death. Between the eighth and ninth centuries, Arab traders and travelers, then African clerics, began to spread the religion along the eastern coast of Africa and to the western and central Sudan (literally, “Land of Black people”), stimulating the development of urban communities. Given its negotiated, practical approach to different cultural situations, it is perhaps more appropriate to consider Islam in Africa in terms of its multiple histories rather then as a unified movement.

The first converts were the Sudanese merchants, followed by a few rulers and courtiers (Ghana in the eleventh century and Mali in the thirteenth century). The masses of rural peasants, however, remained little touched. In the eleventh century, the Almoravid intervention, led by a group of Berber nomads who were strict observers of Islamic law, gave the conversion process a new momentum in the Ghana empire and beyond. The spread of Islam throughout the African continent was neither simultaneous nor uniform, but followed a gradual and adaptive path. However, the only written documents at our disposal for the period under consideration derive from Arab sources (see, for instance, accounts by geographers al-Bakri and Ibn Battuta).