This is the first comprehensive book on the dynamical diffraction of x-rays since the development of synchrotron radiation. There is an introduction to the subject presenting early developments and the basic results, followed by a detailed development of the diffraction and propagation properties of x-rays in perfect crystals and by an extension of the theory to the case of slightly and highly deformed crystals. The last section gives three applications of the theory: x-ray optics for synchrotron radiation, locations of atoms at surfaces, and x-ray diffraction topography. The book is well illustrated and contains a wide range of references to the literature.