 Under this system, a flat tax was imposed on farmers and small traders and collected by government-appointed tax collectors from the Sha'iqiyya tribe of northern Sudan.In bad years, and especially during times of drought and famine, farmers were unable to pay the high taxes.Fearing the brutal and unjust methods of the Sha'iqiyya, many farmers fled their villages in the fertile Nile Valley to the remote areas of Kordofan and Darfur.