Because iron ores were widespread and iron was relatively cheap, the location of iron mines was often determined by the availability of wood, which Britain had in abundance, to make charcoal smelting fuel. Great amounts of iron were needed for the Roman war machine, and Britain was the perfect place to fill that need.
Because iron ores were abundant and iron was inexpensive, the location of iron mines frequently depended on the availability of wood, which Britain had in abundance, to serve as fuel for charcoal smelting. Great quantities of iron were required for the Roman war machine, and Britain was an ideal place to meet that demand.