Saylor.org's Ancient Civilizations of the World/The Iron Age
The Iron Age is the archaeological period generally occurring after the Bronze Age, marked by the prevalent use of iron. The early period of the age is characterized by the widespread use of iron or steel. The adoption of such material coincided with other changes in society, including differing agricultural practices, religious beliefs and artistic styles. The Iron Age as an archaeological term indicates the condition as to civilization and culture of a people using iron as the material for their cutting tools and weapons. The Iron Age is the third principal period of the three-age system created by Danish archaeologist Christian Jürgensen Thomsen for classifying ancient societies and prehistoric stages of progress.
In Africa, where there was no continent-wide universal Bronze Age, the use of iron succeeded immediately the use of stone. Metallurgy was characterized by the absence of a Bronze Age, and the transition from "stone to steel" in tool substances. Sub-Saharan Africa has produced very early instances of carbon steel found to be in production around 2000 years before present in northwest Tanzania, based on complex preheating principles. 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. The Meroitic script was developed in the Napatan Period (c. 700–300 BCE).
Iron metal is singularly scarce in collections of Egyptian antiquities. Bronze remained the primary material there until the conquest by Assyria. The explanation of this would seem to lie in the fact that the relics are in most cases the paraphernalia of tombs, the funereal vessels and vases, and iron being considered an impure metal by the ancient Egyptians it was never used in their manufacture of these or for any religious purposes. It was attributed to Seth, the spirit of evil who according to Egyptian tradition governed the central deserts of Africa.
Discoveries of very early copper and bronze working sites in West Africa in Niger, however, can still support that iron working may have developed in that region and spread elsewhere. Iron metallurgy has been attested very early, the earliest instances of iron smelting in Termit, Niger may date to as early as 1500 BCE. In Central Africa, Iron working may have been practiced as early as the 3rd millennium BCE. It was once believed that iron and copper working in Sub-Saharan Africa spread in conjunction with the Bantu expansion, from the Cameroon region to the African Great Lakes in the 3rd century BCE, reaching the Cape around CE 400.
Sub-Saharan Africa has produced very early instances of carbon steel found to be in production around 2000 years before present in northwest Tanzania, based on complex preheating principles. These discoveries, according to Schmidt and Avery (archaeologists credited with the discovery) are significant for the history of metallurgy.
At the end of the Iron Age, Nubia became a major manufacturer and exporter of iron. This was after being expelled from Egypt by Assyrians, who used iron weapons.
"Iron Age Africa" (Wikipedia) https://en.wikipedia.org/wiki/Iron_Age#Africa