The Sahel or Sahil is in a sense the “coast” of the Sahara and its cities major “ports” in trade circuits linking long-standing regional exchange in the products of different ecozones to the markets of the Mediterranean through the trans-Saharan trade. Despite botanical diversity and the capacity to support high concentrations of humans and livestock, the productivity of this region depends upon a single unpredictable annual rainy season. Long- and short-term fluctuations in aridity have required populations specializing in hunting, farming, fishing, pastoralism, gold mining, and trade to be mobile and to depend upon one another for their survival. While that interdependence has often been peaceful and increasingly facilitated through the shared idiom of Islam, it has also taken more coercive forms, particularly with the introduction of horses, guns, and a dynamic market in slaves. Although as an ecozone the region stretches all the way to the Red Sea, the political Sahel today comprises Senegal, Mauritania, Mali, Burkina Faso, Niger, and Chad—all former French colonies. France’s empire was superimposed upon the existing dynamics in the agropastoral meeting ground of the desert edge. Colonial requirements and transportation routes weakened the links between the ecozones so crucial to the success of states and markets in the region. Despite the abolition of slavery in 1905, France tacitly condoned the persistence of servile relations to secure requisitions of labor, food, and livestock. Abolition set off a very gradual shift from slavery to other kinds of labor patterns which nonetheless drew upon preexisting social hierarchies based upon religion, caste, race, and ethnicity. At the same time, gender and age gained in significance in struggles to secure labor and status. “Black Islam” (Islam noir), both invented and cultivated under French rule, was further reinforced by the bureaucratic logic of the French empire segregating “white” North Africa and “black” sub-Saharan Africa from one another. Periodic drought and famine in the region has prompted a perception of the Sahel as a vulnerable ecological zone undergoing desertification and requiring intervention from outside experts. Developmentalist discourse from the late colonial period on has facilitated the devolution of responsibilities and prerogatives that typically belong to the state to nongovernmental bodies. At the same time, competition over political authority in the fragmented postcolonial states of the Sahel has often reinscribed and amplified status and ethnic differences, pitting Saharan populations against the governments of desert edge states. External and internal radical Islamic movements entangled with black market opportunists muddy the clarity of the ideological and political stakes in ways that even currently (2018) further destabilize the region.