A valuable text for teacher educators, including ECT mentors in schools, on the topic of relational expertise. It provides a critical analysis of current conceptions of the role of teacher educator and a theoretical basis for practice. This book provides a concise and clear cultural-historical perspective of the expertise of teacher educators. The theoretical framework of relational expertise draws upon what matters to both the teacher educator and beginning teacher as they work together on the complex problem of learning to teach. It provides a clear basis for their practice and for what happens in their practice, signalling a way of understanding how to undertake the role of teacher educator in terms of the professional learning of the beginning teacher. Concepts explored include relational expertise, relational agency, common knowledge, the double move, metacommentary, and second order practice, offering a critique of the deconstruction of the act of teaching into bite-size chunks to be memorised. Opportunities for critical reflection are also provided throughout the book, which speaks to teacher educators directly in terms of suggesting a clear theoretical basis for their expertise and how to enact this in practice.