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

TLDR

Copper was produced in the Central African Copperbelt from the 4th–7th centuries CE and traded over large distances from the 9th to the 19th centuries, primarily as cross‑shaped ingots (croisettes) whose form and distribution varied over time and space, and whose patterns have been linked to political entities and socio‑cultural boundaries. The study investigates the spatial distribution of croisettes across time to compare regional patterns. Analysis of croisette distribution across the 2nd millennium CE reveals that identical ingot types were traded from Great Zimbabwe to the Upemba depression, with evolving geographic patterns and styles indicating shifting contacts, new boundaries, and areas of exclusive political influence.

Abstract

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.