Although medieval Arabs and Moors had white slaves as well as black and thus did not practice the purely racial slavery that Europeans carried to the New World in the sixteenth and seventeenth centuries, they generally assigned blacks the most menial and degrading tasks. In southern Iberia the most conspicuous slaves of light-skinned or tawny Moorish masters were black Africans, and it was natural for Christians, as well as Muslims, to begin to associate sub-Saharan African ancestry with lifetime servitude.
George Fredrickson 2002: Racism, A Short History.











