Teachers tend not to like the word ‘expert’ when applied to teaching. So why write a book boldly entitled The Expert Teacher of English ? Partly because, I believe, there are many, many expert teachers, and I wish to challenge what I can see as some professional ‘denial’. I profoundly believe teachers need to be more assertive about their expertise and their professional status; of course, there are many other ways to give expert teaching a title, advanced skills teacher? excellent teacher? highly accomplished teacher? chartered teacher?; there will be discussion below of these current terms. Another, essential reason to claim ‘expert teacher’ now is because of a complex set of factors that combine to give high prominence to the recognition that the teacher is the key variable in improving learning. This may strike readers as something obvious. However, this recognition comes less from teachers themselves and more from the systems within which teachers must operate: educational, professional, social and political. In 1989, Robert Protherough published The Effective Teaching of English (Protherough, Atkinson and Fawcett 1989). It was an excellent and intelligent guide to beginning teachers about how to build on their initial training and to develop in their fi rst few years in teaching. Much terminology has changed, but the great majority of its advice remains valuable. An important difference, twenty odd years later, is that we both know more about highly effective (not just effective) teaching and know that we do not yet know enough.