Iron metallurgy in Africa concerns the origin and development of ferrous metallurgy on the African continent. Whereas the development of iron metallurgy in North Africa and the Horn closely mirrors that of the Ancient Near East and Mediterranean region, the three-age system is ill-suited to Sub-Saharan Africa, where copper metallurgy generally does not precede iron working. Following the beginning of iron metallurgy in Western and Central Africa by 2500 BC - 1000 BC, and possibly earlier, agriculturalists of the Chifumbaze Complex would ultimately introduce the technology to Eastern and Southern Africa by the end of the first millennium AD.

In the first decades of the twenty-first century, radiocarbon and thermoluminescence dating of artifacts associated with iron metallurgy in Nigeria and the Central African Republic have yielded dates as early as the third millennium BC. Although a number of scholars have scrutinized these dates on methodological and theoretical grounds, others contend that they undermine the diffusionist model for the origins of iron metallurgy in Sub-Saharan Africa.Bocoum, H. (ed.) 2004 The Origins of Iron Metallurgy in Africa: New Light on Its Antiquity – West and Central Africa. Geneva:UNESCO. p. 100.

Iron metallurgy may have been independently developed in the Nok culture between the 9th century BCE and 550 BCE. The nearby Djenné-Djenno culture of the Niger Valley in Mali shows evidence of iron production from 250 BCE. The Bantu expansion spread the technology to Eastern and Southern Africa between 500 BCE and 400 CE, as shown in the Urewe culture.K. Shillington, History of Africa (3rd ed. 2005), 61–68.

Origins and spread in Africa

Although the origins of iron working in Africa have been the subject of scholarly interest since the 1860s, it is still not known whether this technology diffused into sub-Saharan Africa from the Mediterranean region, or whether it was invented there independently of iron working elsewhere. Although some nineteenth-century European scholars favored an indigenous invention of iron working in sub-Saharan Africa, archaeologists writing between 1945 and 1965 mostly favored diffusion of iron smelting technology from Carthage across the Sahara to West Africa and/or from Meroe on the upper Nile to central Africa.van der Merwe, N. J. 1980. The advent of iron in Africa. In The Coming of the Age of Iron, eds. T.A. Wertime, J.D. Muhly, pp. 463-506. New Haven: Yale University Press. This in turn has been questioned by more recent research which argues for an independent invention.

The invention of radiocarbon dating in the late 1950s enabled dating of metallurgical sites by the charcoal fuel used for smelting and forging. By the late 1960s some surprisingly early radiocarbon dates had been obtained for iron smelting sites in both Niger and central Africa (Rwanda, Burundi), reviving the view that iron-making was independently invented by Africans in sub-Saharan AfricaTrigger, B. G. (1969). The myth of Meroe and the African Iron Age. International Journal of African Historical Studies 2 :23-50.Diop, C.A. (1976). L’usage du fer en Afrique. Nyame Akuma 53:93-95. as far back as 3600 BCE. These dates preceded the known antiquity of ironworking in Carthage or Meroe, weakening the diffusion hypothesis. In the 1990s, evidence was found of Phoenician iron smelting in the western Mediterranean (900–800 BCE),Descoeudres, E. Huysecom, V. Serneels and J.-L. Zimmermann (editors) (2001) The Origins of Iron Metallurgy: Proceedings of the First International Colloquium on The Archaeology of Africa and the Mediterranean Basin/Aux Origines de la Métallurgie du Fer: Actes de la Première Table Ronde Internationale d’Archéologie (L’Afrique et le Bassin Méditerranéen). Special Issue of the journal Mediterranean Archaeology (volume 14) though specifically in North Africa it seems to date only to the 5th to 4th centuries BCE, or the 7th century BCE at the earliest, contemporary to or later than the oldest known iron metallurgy dates from sub-Saharan Africa. According to archaeometallurgist Manfred Eggert, "Carthage cannot be reliably considered the point of origin for sub-Saharan iron ore reduction." It is still not known when iron working was first practiced in Kush and Meroe in modern Sudan, but the earliest known iron metallurgy dates from Meroe and Egypt do not predate those from sub-Saharan Africa, and thus the Nile Valley is also considered unlikely to be the source of sub-Saharan iron metallurgy.

From the mid-1970s there were new claims for independent invention of iron smelting in central NigerQuéchon, G. and J.-P. Roset (1974). Prospection archéologique du massif du Termit (Niger). Cahiérs ORSTOM, Série Sciences Humaines 11:85-104.Grébénart, D. (1985). La Region d'In Gall-Tegidda n Tesemt (Niger), Programme Archéologique d'Urgence 1977–1981. II: Le Néolithique Final et les Débuts de la Métallurgie. Niamey: Institut de Récherches en Sciences Humaines (Études Nigeriennes, no. 49).Paris, F., A. Person, G. Quéchon and J.-F. Saliège (1992). Les débuts de la métallurgie au Niger septentrional (Aïr, Azawagh, Ighazer, Termit). Journal de la Société des Africanistes 62:55-68. and from 1994 to 1999 UNESCO funded an initiative "Les Routes du Fer en Afrique/The Iron Routes in Africa" to investigate the origins and spread of iron metallurgy in Africa. This funded both the conference on early iron in Africa and the Mediterranean and a volume, published by UNESCO, that generated some controversy because it included only authors sympathetic to the independent-invention view.Bocoum, H. (ed.) 2004 The Origins of Iron Metallurgy in Africa: New Light on Its Antiquity – West and Central Africa. Geneva:UNESCO

Two reviews of the evidence from the mid-2000s found technical flaws in the studies claiming independent invention, raising three major issues. The first was whether the material dated by radiocarbon was in secure archaeological association with iron-working residues. Many of the dates from Niger, for example, were on organic matter in potsherds that were lying on the ground surface together with iron objects. The second issue was the possible effect of "old carbon": wood or charcoal much older than the time at which iron was smelted. This is a particular problem in Niger, where the charred stumps of ancient trees are a potential source of charcoal, and have sometimes been misidentified as smelting furnaces. A third issue is the weaker precision of the radiocarbon method for dates between 800 and 400 BCE, attributable to irregular production of radiocarbon in the upper atmosphere. Unfortunately most radiocarbon dates for the initial spread of iron metallurgy in sub-Saharan Africa fall within this range.

Controversy flared again in 2007 with the publication of excavations by Étienne Zangato and colleagues in the Central African Republic.Zangato, E. (2007) Les Ateliers d’Oboui: Premières Communautés Métallurgistes dans le Nord-Ést du Centrafrique. Paris: Editions Recherche sur les Civilisations (ERC).Zangato, E. and Holl, A.F.C. (2010) ‘On the iron front: new evidence from Central Africa’, Journal of African Archaeology 8:7-23. At Oboui they excavated an undated iron forge yielding eight consistent radiocarbon dates of 2000 BCE. This would make Oboui the oldest iron-working site in the world, and more than a thousand years older than any other dated evidence of iron in Central Africa. Opinion among African archaeologists is sharply divided. Some specialists accept this interpretation, but archaeologist Bernard Clist has argued that Oboui is a highly disturbed site, with older charcoal having been brought up to the level of the forge by the digging of pits into older levels.Clist, B. (2012) Vers une réduction des prejugés et la fonte des antagonisms: un bilan de l’expansion de la métallurgie du fer en Afrique sud-Saharienne, Journal of African Archaeology 10:71-84. Clist also raised questions about the unusually good state of preservation of metallic iron from the site. However, archaeologists such as Craddock, Eggert, and Holl have argued that such disturbance or disruption is highly unlikely given the nature of the site. Additionally, Holl, regarding the state of preservation, argues that this observation was based on published illustrations representing a small unrepresentative number of atypically well-preserved objects selected for publication. At Gbabiri, also in the Central African Republic, Eggert has found evidence of an iron reduction furnace and blacksmith workshop with earliest dates of 896–773 BCE and 907–796 BCE respectively. In north-central Burkina Faso, remains of an iron smelting furnace near Douroula was also dated to the 8th century BCE, leading to the creation of the Ancient Ferrous Metallurgy Sites of Burkina Faso World Heritage Site. In the Nsukka region of southeast Nigeria (now Igboland), archaeological sites containing iron smelting furnaces and slag have been excavated dating to 750 BCE in Opi (Augustin Holl 2009) and 2,000 BCE in Lejja (Pamela Eze-Uzomaka 2009). According to Augustin Holl (2018), there is evidence of ironworking dated to 2,153–2,044 BCE and 2,368–2,200 BCE from the site of Gbatoro, Cameroon.

Archaeometallurgical scientific knowledge and technological development originated in numerous centers of Africa; the centers of origin were located in West Africa, Central Africa, and East Africa; consequently, as these origin centers are located within inner Africa, these archaeometallurgical developments are thus native African technologies. Iron metallurgical development occurred 2631 BCE – 2458 BCE at Lejja, in Nigeria, 2136 BCE – 1921 BCE at Obui, in Central Africa Republic, 1895 BCE – 1370 BCE at Tchire Ouma 147, in Niger, and 1297 BCE – 1051 BCE at Dekpassanware, in Togo.

In 2014, archaeo-metallurgist Manfred Eggert argued that, though still inconclusive, the evidence overall suggests an independent invention of iron metallurgy in sub-Saharan Africa. In a 2018 study, archaeologist Augustin Holl also argues that an independent invention is most likely.