Fredrik Barth is one of the towering figures of twentieth-century anthropology. In a career spanning six decades, Barth first made his mark with a study of ecological relationships among ethnic groups in Swat (Pakistan), followed by studies of political and economic systems in Pakistan and Iran, emphasising the role of agency and social process rather than structure and function. He later carried out fieldwork in western Norway, New Guinea, Oman, Bali and Bhutan, and his voracious appetite for fieldwork as a means to intellectual development is the key to understanding his thought and contributions to anthropology. This intellectual history traces the development of Barth's ideas and explores the substance of his contributions. In so doing, it is also makes a major contribution to the history of anthropology, raising questions to do with the unity and diversity of humanity, cultural relativism and anthropology as a hybrid activity 'between art and science', seen through the lens of one of its most distinguished practitioners. Written in a wonderfully accessible style, Thomas Hylland Eriksen's biographical study reveals the magic of ethnography to professional anthropologists and non-practitioners alike.