In long-ago 1999, the Dyslexia Institute and Plenum Press conceived a plan for two books which would gather the best of current knowledge and practice in dyslexia studies. This would benefit those-but not only those-many individuals who train with us, acquiring a postgraduate certificate and diploma with our higher education partner, the University of York. Since then, the century changed, the hinge of history creaked and Plenum was taken over by Kluwer Academic Publishers, but the first of the pair, Dyslexia in Practice, emerged quickly and on schedule (Townend and Turner, 2000). Written by staff and close associates of the Institute, its chapters were produced under close scrutiny and with the expedition of a command economy. To our delight, the book has seen a success which went beyond the dreams of its editors: it has been adopted by other courses similar to our own and is widely referred to. The same was never likely to be true of The Study of Dyslexia, which was envisaged as a theoretical companion volume written by authors and researchers of international repute. Nearly five years after the idea first took shape, this second volume now arrives to complete the enterprise, but it has been a very different project.