Burkina Faso, Liberia, Guinea-Bissau, Niger and Mauritania. Their traditional society has featured socially stratified castes, from at least the 13th century. The Mandinka society, states Arnold Hughes – a professor of West African Studies and African Politics, has been "divided into three endogamous castes – the freeborn (foro), slaves (jongo), and artisans and praise singers (nyamolo). The freeborn castes are primarily farmers, while the slave strata included labor providers to the farmers, as well as leather workers, pottery makers, metal smiths, griots and others. The Mandinka Muslim clerics and scribes have traditionally been a separate endogamous occupational caste called Jakhanke, with their Islamic roots traceable to about the 13th-century., Quote: "The Jakhanke, who now primarily speak Mandinka, have formed a specialized caste of Muslim clerics and educators since approximately the 13th century". The Mandinka castes are hereditary, and marriages outside the caste was forbidden. Their caste system is similar to those of other ethnic groups of the African Sahel region, and found across the Mandinka communities such as those in Gambia, Mali, Guinea and other countries. Senufo people The Senufo people are found in a region spanning the northern Ivory Coast, the southeastern Mali and the western Burkina Faso. One sub-group, the Nafana, is found in north-western Ghana. The Senufo people have traditionally been a socially stratified society that has included castes and slaves., Quote: "[Castes] are found among the Soninke, the various Manding-speaking populations, the Wolof, Tukulor, Senufo, Minianka, Dogon, Songhay, and most Fulani, Moorish and Tuareg populations". These endogamous divisions are locally called Katioula, and one of the strata in this division includes slaves and descendants of slaves. According to Dolores Richter, the caste system found among Senufo people features "hierarchical ranking including despised lower castes, occupational specificity, ritual complementarity, endogamy, hereditary membership, residential isolation and the political superiority of farmers over artisan castes". Soninke people The Soninke people are a West African ethnic group found in eastern Senegal and its capital Dakar, northwestern Mali and southern Mauritania. Predominantly Muslims, the Soninke were one of the early ethnic groups from Sub-Saharan West Africa to convert to Islam about the 10th century. The contemporary population of Soninke people is estimated to be over 2 million. The cultural practices of Soninke people are similar to the Mandé peoples, and includes social stratification.Monica Bella (1987), AFRICA STUDIES: THE EXPLORATION OF ALTERNATIVE LAND TENURE AND ORGANIZATIONAL ARRANGEMENTS FOR THE BAKEL SMALL IRRIGATED