This report focuses on how four high-performing systems of education designed and deliver high-quality leadership development programs for aspiring principals. While these systems have a strategic, system-wide approach that positions programs within the broader continuum of leadership development, this report focuses on programs that prepare aspiring principals for their future roles and responsibilities. It begins with an overview of the latest research in leadership, which is primarily focused on business leadership. It finds that the best business research programs have the same characteristics as school leadership programs in the top-performing countries: they are highly contextualized and engage leaders in addressing real problems. The report finds, in fact, that some education systems can provide leadership development programs that far surpass those for generalist or executive MBAs. The world's highest-performing school systems have all made extensive investments in school leadership development programs, and these provide some insights. Students in Ontario, Singapore, Hong Kong and Shanghai performed, on average, in the global top ten systems for student achievement in mathematics, literacy and science in the Programme for International Student Assessment (PISA) for 2009 and 2012. But these systems have not always been at the top of the world tables. This report shows how these systems now provide high-quality school leadership development programs that: (1) Are tailored to reforms in each specific education system, so that programs vary to deliver the school leadership that each system needs; (2) Design the training as a practical experience under the guidance of expert leaders; and (3) Overcome the pitfalls of both leadership development in other industries and generalist and executive MBA programs. [The analysis presented in this report was conducted by Learning First.]