Federal and state mandates to improve student achievement for all students necessitate change in the way schools operate and are run. The role of the principal has changed and requires different skills to succeed in the 21st century. However, there are few studies that focus on revealing the perspective of a principal who applied a change theory in a school setting and positively transformed a low performing school into a high performing school. The purpose of this qualitative autoethnography was to study a principal's leadership in a middle school culture as the principal attempted to transform the school from 2005-2008. The leadership framework for the study was the Four Dimensions of Principal Leadership (Green, 2010) and the practices, processes, and procedures embedded within the dimensions used to transform the low performing school into a high performing school. A document/artifact analysis was conducted to reveal leadership practices, processes and procedures the principal used over time. The results of the document analysis indicated the principal utilized knowledge of the Four Dimensions of Principal Leadership and identified nineteen major themes that surround the four dimensions and eight practices that include leadership of the principal, collaboration of the faculty and staff, having high expectations for all students, structuring the school in a nurturing manner, using data to make instructional decisions, aligning the curriculum and using appropriate student interventions, implementing a focused professional development plan for all personnel, and engaging parents in the teaching and learning process. Analysis of data sources indicated that Red Middle School was transformed because the principal changed what was taught, how it was taught and what was expected of students. The culture of the school evolved through a process of implementing the Nurturing Schools Inventory (Green, 2010) which included building relationships with the students, community, staff and the district. The implications of this study can assist aspiring principals in understanding the complex nature of implementing an effective change model to transform a school in the 21st century. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]