In 2009, Metropolitan Nashville Public Schools (MNPS) was on the brink of state takeover, with low academic performance, significant achievement gaps, and a number of schools failing to meet performance targets under No Child Left Behind. Additionally, over the past decade, significant demographic shifts in Nashville have resulted in MNPS becoming much more ethnically and culturally diverse, with students now representing over 120 different countries. The district has also seen a significant increase in the percentage of economically disadvantaged students. Building the leadership capacity of principals in the district was a primary lever for transformational change. A core strategy for building their capacity to change was the implementation of the biannual Principal Leadership Institutes (PLIs). The PLI's were designed as consistent, thoughtful professional learning that was: (1) responsive to MNPS context and needs; (2) drove toward and overarching vision for long-term systemic transformation; and (3) laid the foundation for a district culture of adult learning. Embedded in the model were effective strategies for teaching and learning, and the work of shaping a culture to infuse learning and collaboration throughout the district was begun. Learning opportunities were results based, experiential, and collaborative, and had practical application to the school context. Efforts were also made to scaffold learning experiences between the winter and summer PLIs, and to connect them to ongoing meetings for principals and administrators. Drawing from research and collective years of experience in leadership development, a set of key leadership competencies to guide both the content and design of the PLIs was designed. In 2011, a design team formalized these competencies into the MNPS Leadership Performance Strands and Skills (LPSS). The Annenberg Institute for School Reform at Brown University (AISR) observed and conducted principals' evaluations of the PLIs since their inception, and believes the evolution of principals as transformational leaders make this district one to watch. The purpose of this study is to explore this transformation through the lens of the PLIs as a driver for change. This report captures major findings and the emerging signs of progress and challenge for MNPS during the first six years of PLIs, and it provides recommendations for future development of principals and staff as transformational leaders. [For the full report, see ED574720.]