This book focuses on the practices of middle leaders in schools and other educational institutions. It positions the middle leader as a critical curriculum- and professional-leader and provides a conceptual framework within which to understand middle leading and the conditions that shape it in practice. This is the book I have missed! You know that you have missed some books, the first time you read them. For me this is such a book. From my experiences of having worked as a middle leader for teacher development for the last two decades, I am more convinced than ever that for professional and school-based development to be sustained means recognising the interplay between teachers' past, present and the future practices. This means that professionals, like middle leaders, need methods, models and theories that help them to develop the competencies needed to do this work. This guidance and support is presented in this book. Dr Lisbeth Gyllander Torkildsen, Director of Quality and Development Department, Malmö, Sweden. Middle leaders are the silent, at times overlooked leaders and administrators of professional learning and classroom practice. This book places them at the centre of the action in schools, as agents of professional learning who lead practice through action research. They are the players and the risk takers. This book is rich with vignettes that provide us with the evidence of practice we need as researchers and practitioners to celebrate the importance of middle leading in the life of the school. Unpacking these rich examples of practice using the theory of practice architectures, with additional resources, Grootenboer, Edwards-Groves and Rönnerman show us how and why middle leading matters, and what to do next. Dr Christine Grice, Christine Grice, Lecturer, Educational Leadership Sydney School of Education and Social Work, The University of Sydney, Australia