Oxford Dictionary of Archaeology.
An alloy of copper (typically about 90 per cent) and tin (typically about 10 per cent).
It has many advantages over pure copper, notably a lower melting point, better casting properties, and a greater hardness when cold.
The big disadvantage was that tin is relatively scarce compared to copper and thus long-distance trading links were necessary in order to secure supplies.
The earliest use of bronze in Europe was probably in the lower Danube or Carpathian region during the second half of the 3rd millennium bc,
influenced by metalworking traditions still further to the east in the Caucasus.