This book is about the generative nature of leading practices when teachers, as learners, participate in long term action research projects for the purpose of professional development. This book also shows how practices of professional learning and practices of leading can be understood as related (and developed) in ecologies of practices; the authors show how these are explicitly connected. These findings direct readers to the connectivity between professional learning and leading practices that over time - after participating in long term action research programs - emerged as 'significant' yet 'unexpected' outcomes.