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
Rail transport in Chad N'Djamena to Moundou and Koutéré on the Cameroon border (528 km), and one from the capital to the border with Sudan (836 km) via Abéché and Adré. The lines are to be built to standard gauge and for 120 km/h running, and equipment for the line will be sourced in China. Rail transport in Chad Up to 2012 Chad had no rail system. Two lines are planned to Sudan and Cameroon from the capital with construction expected to start in February 2016 and be complete in 4 years. A 1905 book describes the history of a German railroad syndicate's exploration