This chapter addresses the history of the Ahl Guennar, a confederation of families known for their mastery of l’ḥjāb, whose members are dispersed among several villages just north of the Senegal River. The Ahl Guennar’s ambiguous racial identity, their shifting religious and occupational affiliations, their secrecy and enigmatic reputation, and their long history in the region make them a compelling case study for the role of Islamic esoteric knowledge in Mauritania’s mercurial political and cultural environment. Claiming descent from a well-known religious figure and a miraculous origin story for their principal village, the Ahl Guennar established themselves by the seventeenth-century learning and teaching the Qur’ān and its sciences and carving out an exclusive space for themselves in the political dynamics of the Gebla, or southwestern region of Mauritania. This chapter deals with the long-term history of the family to better understand how they deploy these stories to claim religious and social roles in the region and to illustrate how Islamic knowledge is transmitted and the ways these Muslim mediators of the spiritual and material worlds depended upon this knowledge to thrive.