The discovery of bronze enabled people to create metal objects such as tools, weapons, armor, and building materials which were harder and more durable than previously possible. Initially, bronze was made out of copper and arsenic with the earliest artifacts so far known coming from the Iranian plateau in the 5th millennium BC. It was only later that tin was used, becoming the major non-copper ingredient of bronze in the late 3rd millennium BC.
The archeological period in which bronze was the hardest metal in widespread use is known as the Bronze Age. The Bronze Age was followed by the Iron Age starting from around 1300 BC and reaching most of Eurasia by about 500 BC, although bronze continued to be much more widely used than it is in modern times.
Bronzes are typically very ductile alloys, considerably less brittle than cast iron. It only oxidizes superficially. Once a copper oxide (eventually becoming copper carbonate) layer is formed, the underlying metal is protected from further corrosion.
Bronze is an alloy consisting mostly of copper, tin, and other metals like aluminium, manganese, nickel, or zinc. It machines beautifully and looks great when highly polished or when it has some patina.