the nobles by the tribal chiefs. The chietain is the overlord during times of war, and receives tribute and taxes from tribes as a sign of their submission to his authority. The vassal-herdsmen are the second free strata within Tuareg society, occupying a position just below that of the nobles. They are known as ímɣad (Imghad, singular Amghid) in the Tuareg language. Although the vassals were also free, they did not own camels but instead kept donkeys and herds of goats, sheep and oxen. They pastured and tended their own herds as well those owned by the nobles of the confederation. The vassal strata have traditionally paid an annual tiwse, or tribute to the nobles as a part of their status obligations, and also hosted any noble who is traveling through their territory. In late medieval era, states Prasse, this weapon monopoly broke down after regional wars took a heavy toll on the noble warrior strata, and thereafter the vassals carried weapons as well and were recruited as warriors. After the start of the French colonial rule which dislodged the nobles from their powers over war and taxation, the Tuaregs belonging to the noble strata disdained tending cattle and tilling the land, seeking instead warrior or intellectual work. A semi-noble strata of the Tuareg people has been the endogamous religious clerics, the marabouts (Tuareg: Ineslemen, a loan word that means Muslim in Arabic). After the adoption of Islam, they became integral to the Tuareg social structure. According to Norris, this strata of Muslim clerics has been a sacredotal caste, which propagated Islam in North Africa and the Sahel between the 7th and the 17th centuries. Adherence to the faith was initially centered around this caste, but later spread to the wider Tuareg community. The marabouts have traditionally been the judges (qadi) and religious leaders (imam) of a Tuareg community. According to the anthropologist Jeffrey Heath, Tuareg artisans belong to separate endogamous castes known as the Inhædˤæn (Inadan). These have included the blacksmith, jewelers, wood workers and leather artisan castes. They produced and repaired the saddles, tools, household items and other items for the Tuareg community. In Niger and Mali, where the largest Tuareg populations are found, the artisan castes were attached as clients to a family of nobles or vassals, and carried messages over distances for their patron family. They also are the ones who traditionally sacrifice animals during Islamic