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.