This book contains reviews of a selection of recent research conducted by members of the International Successful School Principalship Project (ISSPP), together with two closely related chapters by one of the editors. Initiated in 2001, the ISSPP has grown from the original founding group of six countries to become the largest and most enduring body of multi-perspective, multi-layered collaboratively designed and conducted research about successful school principalship. Carried out by more than 100 academics in 27 countries, the research aims to better understand the work of successful school principalship across a wide range of national contexts. Its ambition over the next decade is to extend the reach of its work further to include research by academics from the Global South, the Middle East, and Asia, all of which remain largely under-represented in the field.