The purpose of this study was to investigate the impact of principal participation in the Davis Principal Coaching Initiative, an executive leadership capacity building development program, on leader practice and professional practice of teachers. This mixed-method comparative case study investigated the following five research questions: (1) How does participation in the Davis Principal Coaching Initiative (DPCI) prepare principals to become effective instructional leaders? (2) How does the DPCI influence the knowledge, beliefs and leadership practices of urban school principals? (3) How does an urban school principal create and sustain organizational structures and processes that promote effective teacher practice and improve student outcomes? (4) What leadership support structures enable leader practice? And, (5) How can the VAL-ED instrument serve as a coaching tool to assist principals to become effective instructional leaders? Quantitative data were collected from the results of the Vanderbilt Assessment of Leadership in Education (VAL-ED) survey, an instrument that provided a summary of the principals, teachers and supervisors' perceptions on the principal's leadership behaviors (Murphy et al. 2006). Qualitative data were collected from pre-post interviews, observations and document analysis. Key findings revealed that the DPCI provided the principals with professional development that increased their capacity as instructional leaders; and the coaching structure helped the principal implement district initiatives, and provided the principals with moral and daily support at the school site. Findings also indicated that the principals displayed instructional and learning-centered leadership behaviors, such as monitoring and evaluating the instructional program, creating a positive organizational culture and defining and communicating the school goals. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]