Leadership is an ill-defined domain, drowning in abstract theories and models of expertise. School leadership suffers from this lack of a satisfactory and useful definition of leadership, and has of late been drawn in to generic approaches to school improvement which have left the workforce feeling anything but “well led’. How do we put "substance’ back in to school leadership? This book draws on the lessons of cognitive science and explores the specific things that school leaders do, arguing for a notion of school leadership rooted in the realities of leaders’ daily experiences. It presents a case for how school leaders can develop their expertise and, in doing so, places domain-specific knowledge at the heart of school improvement efforts.