The rapid growth of the aluminium industry during the last hundred years reflects the status of aluminium as the quintessentially modern metal. Given its impact on every facet of modern life, its aptitude for academic analysis is only rivalled by the versatility of the metal in industrial application. While during the 19th century aluminium was the source of luxury goods for the rich few, during the First World War it was subjected to strategic considerations by belligerent states. It had become a warfare metal. It remained a military-strategic metal well into the 1950s, before it regained a position as a metal for civilian consumption, this time for the masses. This book takes a historical approach, informed by an institutionalist perspective, to elucidate the political economy of the aluminium industry in the twentieth century. It is structured as a series of analyses of the interactions between the state and the corporations in different countries. By looking at business-government relationships we can better grasp the linkages between the aluminium industry and the two key features of the history of the twentieth century: The rise of the industrial warfare state and its subsequent replacement by the welfare state.