History of Chad Africa's major language groupings south of the Sahara Desert (except Khoisan, which is not considered a valid genetic grouping anyway), i. e. the Afro-Asiatic, Nilo-Saharan and Niger–Congo phyla, originated in prehistoric times in a narrow band between Lake Chad and the Nile Valley. The origins of Chad's peoples, however, remain unclear. Several of the proven archaeological sites have been only partially studied, and other sites of great potential have yet to be mapped. At the end of the 1st millennium AD, the formation of states began across central Chad in the sahelian zone between the desert and the savanna. For
Chad–Sudan relations Chad–Sudan relations The populations of eastern Chad and western Sudan established social and religious ties long before either nation's independence, and these remained strong despite disputes between governments. In recent times, relations have been strained due to the conflict in Darfur and a civil war in Chad, which both governments accuse the other of supporting. Herdsmen have in both countries freely crossed the 950-kilometer border for centuries. Muslims in eastern Chad often traveled through Sudan on the hajj, or annual pilgrimage to Mecca, and many young people from eastern Chad studied at Islamic schools in Pickens. In addition, Sudan's coffee