It is almost exactly half a century since the publication of R. A. Bagnold's classic book The physics of blown sand and desert dunes, and it is a tribute to the quality of Bagnold's work that many of the fundamental principles which he developed remain valid today. His book continues to be essential reading for any serious student of aeolian processes. However, the past two decades have seen an explosion in the scale of research dealing with aeolian transport processes, sediments, and landforms. Some of this work has been summarized in review papers and edited conference proceedings, but this book provides the first attempt to review the whole field of aeolian sand research. Inevitably, it has not been possible to cover all aspects in equal depth, and the balance of included material naturally reflects the authors' own interests to a significant degree. However, our aim has been to provide as broad a perspective as possible, and to provide an entry point to an extensive multi-disciplinary scientific literature, some of which has not been given the attention it deserves in earlier textbooks and review papers. Many examples are drawn from existing published work, but the book also makes extensive use of our own research in the Middle East, Australia, Europe, and North America. The book has been written principally for use by advanced undergraduates, post graduates, and more senior research workers in geomorphology and sedimentology.