The making of steel was the crucial technological invention that made iron-based alloys preferable to copper-based alloys. Three different methods of making steel from iron were developed in the ancient world. The earliest, in the eastern Mediterranean where the Iron Age began about 1200 B.C., produced steel from low-carbon blooms through carburization and complex forging. In China, where iron production was common in North China by the 6th century B.C. and iron objects of earlier date have been found, high temperature smelting produced a high-carbon cast iron and steel through de-carburization. In southeast Asia iron objects were known in 1200 B.C. and earlier, and iron technology may have developed independently there; discoveries there have not been completely documented and the relationship to Chinese iron metallurgy is not yet known. In Africa a third method yielded high-carbon steel as a smelting product, and here both Mediterranean and Far Eastern influences are detectable. Various ethnographic and archaeological evidence is explored to trace the history of steelmaking. -- AATA