This book offers a unique perspective on the principles and developmental pathways (i.e., practices, and processes) associated with developing leaders and leadership. Unlike most offerings on the topic of leadership development, it adopts an evidence-based approach to the scientific study of developing leaders and leadership, including the underlying theories that support this study. Focused on the processes associated with development within and across levels, the author presents a comprehensive summary of what we know about the developmental pathways associated with developing leaders and leadership, practices that motivate effective processes, and the theoretical principles that guide the study and understanding how individuals and collectives develop (i.e., change over time) in ways that increase their respective capacities for leadership. This book will appeal to those interested in understanding how leaders develop and the differences between developing leaders and developing leadership. It draws from theory and  research from management, psychology, sociology, and education.