This book represents a highly original, major new contribution to one of the most important and hotly contested issues concerning the book of Isaiah: who wrote it. The author's provocative and important conclusions point to the key role from beginning to end of the so-called "Deutero-Isaiah, " hitherto believed to have been merely the author of chapters 40-50. Williamson's book, based on a more rigorous methodology than ever before attempted, sheds much new light on many passages of Isaiah, and is certain to have significant influence on all future work on the subject.