Between the beginning of the fifteenth century and the end of the eighteenth, millions lived and died as slaves in African Muslim societies. From the Mediterranean coast to the grasslands of West Africa, in the Nile Valley and the Horn, and all along the Indian Ocean littoral, Muslims predominated or exercised great influence. In all these regions slavery was economically, socially, and politically important, and its scale increased throughout our period before reaching wholly unprecedented levels in the nineteenth century. Islamic principles and practices shaped the nature of slavery in Muslim societies, but they did so in uneven and contingent ways. In this chapter, we will examine the ways in which Islamic ideas about slavery were negotiated in the historical experience of Muslim Africans. There are three major components of any system of slavery: reduction of human beings to servitude, distribution of the enslaved within and between societies, and the nature of servitude within a society. These categories are utilitarian, not absolute. Biological reproduction of slaves belongs in categories one and three. Category three implies the continuous reproduction of the meanings of category one without the initial act of capture or birth. Examples could be multiplied. The categories are heuristic aids, not precise hermeneutical tools. In these sections we will survey Islamic legal, intellectual, and moral discourses on slavery in relation to the historical record. This initial discussion will treat themes common to all of Islamic Africa, providing a necessary context.