The technological advances made during the Bronze and Iron Ages could not have happened without charcoal. To make bronze and iron, the high temperatures reached in a charcoal fire were essential.
The picture shows a charcoal clamp with a fire burning inside. Soil or turf covered the clamp to cut off the oxygen to the flames inside. In this way the fire consumed the natural gases in the wood instead of using oxygen. The gases in the timber burned off, to leave carbonised wood (charcoal).