The Iron Age reached Central Africa more or less at the same time it reached western Europe, some 3,000 years ago. The hallmark of the new era was technological innovation, but the social and economic changes that metalworking brought about were fundamental to the agricultural communities—if not to the hunting communities—of the tropics. Ironworking, unlike agriculture, was not a local invention but a skill that spread from community to community as the superiority of metal tools and weapons came to be recognized. Iron smelting came into Central Africa from two directions. In the northwest the oldest source of the new knowledge was on the Nigerian plateau. The skill necessary to dig pit furnaces and surround them with ranks of bellows spread among the Bantu-speaking peoples of the western forest. Gradually the polished stone tools that they had perfected were replaced by much more expensive but effective iron ones. Initially iron was probably used mainly for small and valuable objects such as razors, needles, and knives; later, as the smelting technique became more commonplace, iron came to be used for cutlasses, axes, and, eventually, hoes, which replaced the old wooden digging sticks.

The second source of technical information in Central Africa was probably the middle valley of the Nile, where the city of Meroe had been an early industrial site with a huge charcoal industry and great piles of iron slag surrounding its furnaces. The eastern tradition of smelting used furnaces as well as bellows to create the necessary draft with which to turn charcoal and ironstone into wrought iron and molten waste. The iron masters became revered craftsmen and were accorded a quasi-religious status. They lived in some seclusion and often commanded a degree of political authority over their neighbours. Legends of blacksmith-princes became commonplace in the historical folklore of Central Africa. Iron became important not only in the immediate locality but also in a developing interregional trade. Although ironstone and wood for charcoal were relatively common in most areas, the best smiths could nevertheless command a premium for their wares, and in some regions of deep blown sand or wide alluvial soils, where ores were not available, iron tools and weapons had to be bought from itinerant tinkers.

Iron was a valuable commodity, both raw in wrought bars and worked into spears or machetes. Even more valuable, however, was copper. Central Africa had no Copper or Bronze Age in the last millennium bc, and it was in the Iron Age that the value of copper came to be recognized. Copper was particularly appreciated for its colour and lustre and was used for personal jewelry, rings, bangles, chains, necklaces, and hair ornaments—all made with great craftsmanship and given to persons loved or revered. Copper was also used in the ornamenting of personal belongings, the inlaying of decorations on knife handles, the binding of spear hafts with fine copper wire, and the embellishing of shields with burnished copper nails. Much of the copper mined in Central Africa was used to furnish the graves of important people with beautiful objects. The demand for fresh copper rose with each new generation. In particular, the development of new political authorities in the Iron Age led to the need for court regalia for chiefs and kings. Copper was used not only for its visual brilliance but also for the musical quality of the copper instruments that accompanied the nobility on their progress around their domains.

The three main zones of copper working in Central Africa were the Nile watershed, the eastern savanna, and the southwestern forest. Each industrial complex was a thousand miles from the next, and trade intensified as the demand for copper increased. The oldest and largest mines were those of the east. By the end of the 1st millennium ad, the mines of what is now Katanga (Shaba [“Copper”]) province of Congo (Kinshasa) were casting copper ingots into molds of standard sizes for the international traffic. The region remained one of the world’s greatest copper-mining areas for the next thousand years. In the north the copper was used to enhance the wealth and prestige of the local population, but it also fed into the long-distance trade networks of the southern Sahara, particularly after these had been strengthened and organized by Muslim merchants and entrepreneurs in the 14th and 15th centuries. The third copper complex, on the lower Congo River, remained an important but localized industry until a later date. At the end of the 16th century, however, the miners discovered a new outlet for their copper in Europe and sold large quantities to sea merchants from the Netherlands in exchange for Indian textiles, Chinese porcelain, South American tobacco, and stone jars of Dutch gin.