For the whole of the eighteenth century and much of the nineteenth, a belt of coastal smelters--using local coals and ores from Cornwall, Cuba, and Chile--produced virtually all of Britain's copper, and much of the world's. Copper brought considerable wealth to Swansea, the center of the industry, and to several neighboring towns. But there was a price for the prosperity. The billowing clouds of toxic, foul-smelling smoke that copper production also produced ruined crops and killed livestock, setting farmers against townsmen and the Welsh-speaking Cymry Cymraeg against their Anglo-Welsh cousins. King Copper is the first history to document the social and environmental impact of the copper industry in south Wales during this period.