Abstract
This article is a revised version of the text of a public lecture delivered by the Assistant Director of the B.I.E.A. at the University of Nairobi in April 1975, and at the British Academy, London, the following month. Two distinct streams are recognised in the spread of the Early Iron Age Industrial Complex into subequatorial Africa. They are here defined with particular emphasis on their chronology, material culture and food-producing economy. The reconstruction thus obtained from exclusively archaeological sources is shown to bear a remarkable resemblance to some recent views on the detailed pattern of expansion of the Bantu languages.