This monograph presents a unified and coherent account of an important, focused area of rare-earth magnetism -- magnetic structures and excitations -- which both reflects the nature of the fundamental magnetic interactions and determines many of the characteristic properties of metals. The authors concentrate on the essential principles and their applications to typical examples, generally restricting the discussion to the pure elements and considering alloys and compounds only when they are instructive in illuminating particular topics. Both authors have been involved for some time in the...