de Sardan, Tal Tamari and other scholars. According to the medieval and colonial era descriptions, their vocation has been hereditary, and each stratified group has been endogamous. The social stratification embedded slavery, wherein the lowest strata of the population inherited slavery, and second the Zima or priests and Islamic clerics had to be initiated but did not automatically inherit that profession, making the cleric strata a pseudo-caste. According to Ralph Austen – a professor emeritus of African history, the caste system among the Zarma people was not as well developed as the caste system historically found in the African ethnic groups further west to them. The different strata of the Zarma-Songhai people have included the kings and warriors, the scribes, the artisans, the weavers, the hunters, the fishermen, the leather workers and hairdressers (Wanzam), and the domestic slaves (Horso, Bannye). Each caste reveres its own guardian spirit. Some scholars such as John Shoup list these strata in three categories: free (chiefs, farmers and herders), servile (artists, musicians and griots), and the slave class. The servile group were socially required to be endogamous, while the slaves could be emancipated over four generations. The highest social level, states Shoup, claim to have descended from king "Sonni 'Ali Ber" and their modern era hereditary occupation has been Sohance (sorcerer). The traditionally free strata of the Zerma people have owned property and herds, and these have dominated the political system and governments during and after the French colonial rule. Within the stratified social system, the Islamic system of polygynous marriages is a part of the Zarma people tradition, with preferred partners being cross cousins, and a system of ritualistic acceptance between co-wives. This endogamy is similar to other ethnic groups in West Africa. Central Africa Mandara people The Mandara people are a Central African Muslim ethnic group found in north Cameroon, northeastern Nigeria, and southeastern Chad.E Mohammadou (1982), Le royaume du Wandala ou Mandara au XIXe siecle, African Languages and Ethnography 14, Tokyo, pages 7-9 They have lived in the mountainous region and valleys north of the Benue River in Cameroon, converted to Islam sometime around the 16th century, and have long been a part of the Mandara Sultanate. The Mandara society developed into a socially stratified system, with Sultan and royalty, farmers, horse breeders, artisans, iron workers and smiths forming a distinct endogamous occupation-inheriting castes. The caste system among the Mandara people integrated