This book examines British imperial attitudes towards China during their early encounters from 1792 to 1840. It makes the first attempt to bring together the political history of Sino-western relations and cultural studies of British representations of China, as a new way of understanding the origins of the Opium War - a deeply consequential event that arguably reshaped relations between China and the West for the next hundred years. The book focuses on the crucial half-century before the war, a medium-term (moyenne durée) period that scholars such as Kitson and Markley have recently compared in importance to that of American and French Revolutions. Creating the Opium War investigates a range of Sino-British political points of connection, from the Macartney embassy (1792-94), through the Amherst embassy (1816-17) to the Napier incident (1834) and the lead-up to the opium crisis (1839-40). The book shows that throughout this period, Britain harboured increasingly hostile feelings towards China, but at the same time, British opinion-formers and decision-makers disagreed with each other on fundamental matters such as whether to adopt a pacific or aggressive policy towards the Qing and the disposition of the Chinese emperor. It examines a wealth of primary materials, some of which have not received sufficient attention before, focusing on the perceptions formed by those who had first-hand experience of China or possessed political influence in Britain. This study ultimately reveals how the idea of war against the Chinese empire was created on the basis of these developing imperial attitudes.