In reviewing the work of the BIEA this volume summarises the history and development of Eastern Africa. Prominent subjects include: the town of ntusi in the 11-14th cents, and the background to the inter lacustrine kingdoms; irrigation cultivators at Engaruka below the rift escarpment 300 to 500 years ago; the Siriwake livestock specialists in the high grasslands until the Maasai Revolution; salt and iron industries through the ages; the flowering of Swahili towns and their place in the world of islam; Kilwa, the 14th century palace of Husuni Kubwa and the Zimbabwe gold trade.