In the first millenium BC, early cities and towns were created by Mande peoples related to the Soninke people, along the middle Niger River in central Mali, including at Dia which began from around 900 BC, and reached its peak around 600 BC, and Djenne-Djenno, which lasted from by around 300 BC to 900 AD. By By the 6th century AD, the lucrative trans-Saharan trade in gold, salt and slaves had begun, facilitating the rise of West Africa's great empires.