The book has been planned both for final year undergraduates and as a reference book for research. It is suitable as a course book on radio propagation for students of physics or electrical engineering or mathematics. Some of the topics are presented from an elementary viewpoint so as to help undergraduates new to the subject. The later parts are more advanced. The subject is very large and has seen many important recent advances. Some topics have had to be treated only briefly, but there is a full bibliography with about 600 references.