See how the iSTEP Institute has transformed teacher preparation around the world. The contributors to this volume document and analyze the evolution of an international, organic network of collaborating teacher educators. Educators at the Stanford Teacher Education Program launched the iSTEP Institute, a professional learning and development program for teacher educators from across the globe. This international movement seeks to construct and implement exemplary teacher preparation. Chapter authors argue that there are several shortcomings with how we currently conceptualize (1) the nature of reform in teacher education, (2) the role of theory in transforming educational institutions, and (3) the transnational diffusion of innovation and best practices in teaching and teacher education. They articulate a new formulation of effective systemic reform. This book shows how the iSTEP Institute has been a reform catalyst for teacher preparation by embedding and transforming the key institutional components of universities, NGOs, foundations, schools, and school governance. Case examples demonstrate how the activities of this reform network have transformed teacher education in several nations across the global north and south. Book Features: Identifies key design principles for consequential teacher preparation on a global level. Offers case examples that demonstrate the power and transferability of design principles across social, political, and cultural contexts. Elevates the power of organic, relational networks as a catalyst and engine for effective reform in teacher education. Draws on principles of teacher preparation from the iSTEP Institute and the Stanford Teacher Education Program (STEP) whose model of preparation is internationally renowned. Demonstrates how effective school/university partnerships can evolve to support long-term reform in teacher preparation. Lotan directed STEP for over a decade Lit is the current faculty director LeTendre worked with the Program for Complex Instruction during his time at Stanford. Contributors include leading scholars of teacher education from around the world, all of whom participated in the iSTEP Institute.