John Palmer was the most influential and wealthiest British merchant in British India for the first three decades of the nineteenth century. He ran an `agency house', a global commercial firm involved in banking, the opium trade, shipping, plantation agriculture and trade with Britain, Europe, China, south east Asia and the USA. When his firm went bankrupt in 1830, thousands of people, European and Indian, were ruined, triggering the worst commercial crisis in British India up to that time. This book, the first major study of a British agency house in India, presents an account of both of Palmer's business and personal life, showing how his personal relations and circumstances shaped his commercial strategies, with ultimately disastrous consequences for Anglo-Indian relations as well as his clients.