This dissertation analyzes instructional leadership and evaluation protocols from a large, diverse district in the Southeastern United States in order to investigate layers of accountability and tensions created when principals are asked to fill the dual roles of both instructional leader and supervisor in a newly implemented teacher evaluation system reform. For this dissertation I investigate the role of the principal as a colleague and mentor and compare this with the role of the principal as supervisor and evaluator in hierarchical systems. I include the role of the peer evaluator, a new position, in my analysis. Critical discourse analysis is utilized, primarily informed by Fairclough's Three Dimensional Framework for investigating discourses of instructional leadership and attendant Foucauldian notions of governability. The analysis shows that district administrators, principals, peer evaluators, and teachers employ nuanced definitions of instructional leadership. These definitions are impacted by deeply entrenched norms of what it means to be a principal and a teacher within the hierarchy of the school district of interest. Principals in this study were able to navigate the dual roles of instructional leadership and supervision largely due to how they and teachers defined the role of instructional leadership. The teacher evaluation reform has brought with it a new perspective on the hierarchy coinciding with new power dynamics. The results of this study have implications for our understanding of the role of the principal and how that role is constructed by principals and teachers as well as district administrators and peer evaluators.