Toward the end of the seventeenth century, marabout Nasir al-Din launched a religious movement against transatlantic slaving but for the Islamization of the Senegal valley. French colonial official Louis Chambonneau, stationed at the French outpost of St. Louis at the mouth of the Senegal river, was an eyewitness whose reporting of the events to his superiors remains one of the best first-hand accounts Nasir al-Din’s movement. Nasir al-Din was born in the southern Sahara to an elite family of the Traza Moors (so-called “Berbers”). Chambonneau referred to the movement as Toubenan (from the Wolof tuub, “conversion”). Chambonneau and many after him agreed the success of the Toubenan religious movement, though Nasir al-Din was killed, was due to the negative effects wrought by transatlantic slaving.