During the Bronze Age, humans in the Mideast learned how to smelt, melt, cast, rivet, and forge copper and bronze (the last one being harder, more resistant to corrosion, and having a lower melting point). Much of the copper came from Cyprus’s island and most of the tin from the Cornwall region. Because copper and bronze cannot be hardened by heat-treatment, they have to be hammered for a long period of time.
Before the Iron Age, iron was not thoroughly understood – plus, it didn’t significantly improve on the qualities of existing bronze artifacts (unalloyed iron is soft, doesn’t hold an edge as well, and needs more maintenance). Iron ores were, however, more widely available.
In the medieval period, blacksmithing was considered part of the set of seven mechanical arts. The original fuel for forge fires was charcoal (coal only began to replace it during the 17th century).