Copper, Trade and Polities: Exchange Networks in Southern Central Africa in the 2nd Millennium CE

A rare, scattered resource in Central Africa, copper was produced in the Copperbelt since the 4th–7th centuries CE and traded over large distances from the 9th to the 19th centuries. It was exchanged mainly in the form of cross-shaped ingots, also called croisettes, varying in form and size over time and space. In this article, we explore and compare the spatial distribution of these ingots over time. This approach offers an opportunity to study pre-colonial trade. Indeed, during the 2nd millennium CE, the use of the same type of ingots is attested in distant regions, from the Great Zimbabwe area to the Upemba depression (north Katanga, Democratic Republic of Congo DRC). Over the centuries, changes in geographic distribution patterns and styles indicate shifts in contacts and the appearance of new boundaries. These variations reflect changes in the regional distribution networks and suggest areas of exclusive political influence. Historical information available for the 19th century shows that it is possible to link the diffusion of copper with political entities, a hypothesis supported by evidence related to other kinds of production, such as ceramics and salt. For remote periods, confrontation of the croisettes’ distribution with other aspects of material culture suggests that such links between socio-political spaces and copper distribution may also have occurred in the distant past.