Abstract: From 8,000-5,500 BP, the African Sahara was a centre for domestication of millets and sorghum. Agriculture in the region was extinguished following a sustained drought after 5,450 BP, but may have contributed to the development of the Nile Valley as one of the greatest agro-urban cultures of the ancient world. In Central Europe, after 8,500 BP, farming was introduced by migrants from the Near East who slowly travelled northwestwards along the fertile river valleys from the Balkans towards the Atlantic coast. Other seaborne migrants brought farming to southern Europe via the Mediterranean. Complex urban cultures did not develop in this region for many millennia. Agro-urban cultures developed separately in Mesoamerica, the Andes, and parts of North America once the indigenous crops could be cultivated under high yield conditions. Social collapse and simplification occurred repeatedly in several parts of the continent, probably due to a combination of climatic and social factors.

Keywords: millet, sorghum, Nile Valley, Mesoamerica, Mayan collapse, South America, North America, farming,