It is now widely accepted that improving schools invest in teacher leadership and build the capacity for improvement by distributing leadership responsibilities to teachers. In primary, secondary and special schools, teachers are uniquely placed to influence the quality of teaching and learning and they are important gatekeepers to development and change. This book explores how teacher leadership is an intrinsic and important part of school and classroom improvement. It investigates teacher leadership in action and considers the roles, responsibilities and influence of teachers who lead. It considers the implications of teacher leadership for teachers' professional development and focuses on ways in which this important form of leadership can be fostered and enhanced. The central message in this book is that teachers play a critical role in leading improvement in the classroom and school level and that this form of leadership contributes directly to raising achievement among learners. This book is crucial reading for all those who are concerned with teacher and school development, school leadership and school improvement.