section_path: Chronology/Africa
section_name: Africa
paragraph_text: Africa
  
  Early evidence for iron technology in Sub-Saharan Africa can be found at sites such as KM2 and KM3 in northwest Tanzania and parts of Nigeria and the Central African Republic. Nubia was one of the relatively few places in Africa to have a sustained Bronze Age along with Egypt and much of the rest of North Africa.
  
  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 2631–2458 BC at Lejja, in Nigeria, 2136–1921 BC at Obui, in Central Africa Republic, 1895–1370 BC at Tchire Ouma 147, in Niger, and 1297–1051 BC at Dekpassanware, in Togo.
  
  Very early copper and bronze working sites in Niger may date to as early as 1500 BC. There is also evidence of iron metallurgy in Termit, Niger from around this period. Nubia was a major manufacturer and exporter of iron after the expulsion of the Nubian dynasty from Egypt by the Assyrians in the 7th century BC.
  
  Though there is some uncertainty, some archaeologists believe that iron metallurgy was developed independently in sub-Saharan West Africa, separately from Eurasia and neighboring parts of North and Northeast Africa.
  
  Archaeological sites containing iron smelting furnaces and slag have also been excavated at sites in the Nsukka region of southeast Nigeria in what is now Igboland: dating to 2000 BC at the site of Lejja (Eze-Uzomaka 2009) and to 750 BC and at the site of Opi (Holl 2009). The site of Gbabiri (in the Central African Republic) has yielded evidence of iron metallurgy, from a reduction furnace and blacksmith workshop; with earliest dates of 896–773 BC and 907–796 BC, respectively. Similarly, smelting in bloomery-type furnaces appear in the Nok culture of central Nigeria by about 550 BC and possibly a few centuries earlier.
  
  Iron and copper working in Sub-Saharan Africa spread south and east from Central Africa in conjunction with the Bantu expansion, from the Cameroon region to the African Great Lakes in the 3rd century BC, reaching the Cape around 400 AD. However, iron working may have been practiced in central Africa as early as the 3rd millennium BC. Instances of carbon steel based on complex preheating principles were found to be in production around the 1st century CE in northwest Tanzania.
  
  Dates are approximate; consult particular article for details