Book excerpt: This book provides a unique map of the focus and directions of contemporary research on school leadership since 2000 in 24 countries. Each of these directions has its own particular cultural, educational and policy history. Taken together, the various chapters in the volume provide a rich and varied mosaic of what is currently known and what is yet to be discovered about the roles and practices of principals, and their contributions to the improvement of teaching and the learning and achievement of students. The particular foci and methodological emphases of the research reported illustrate the different phases in the development of educational policies and provision in each country. This collection is an important addition to existing international research that has shown beyond any reasonable doubt that the influence of school principals is second only to that of teachers in their capacity to impact students’ progress and achievement and to promote equity and social justice.