This book is a study of the traditional relationships that exist in Oman between land and social organisation, and how they have evolved. The author starts with the theme of aridity and, using the extensive literature of the 1200 year old Ibadi community to supplement his field work, shows how the techniques of water exploitation have influenced the countrys social organisation and its political ideology. He describes how the settlement organisation has evolved in two stages; the first in the years before Islam when the Persians irrigated the land using aflaj or horizontal water channels; the second after the Arabs had overthrown the Persians and, influenced by Ibadism, established a more democratic society dominated by a strong tribal structure in the villages. The tribal structure is then examined in detail and the author shows how close the links are between the Islamic ideology, land use, and social organisation. As a contribution to the human geography of Oman as well as to general knowledge of the Middle East the book will interest Arabists, Islamic historians and social anthropologists, as well as hydrologists and geographers.