In 2004 the General Assembly of the State of Ohio (USA) enacted Senate Bill 2, which created the Educator Standards Board "to develop and recommend to the state board of education standards for entering and continuing in the teaching and principalship professions". Since that time the Ohio Department of Education has established a coherent leader development system to strengthen the accountability and performance of school principals under the standards that were adopted. This article reports on the national and international context of such work, related research, the development of the Ohio Principal Standards, the alignment of the standards with national standards, the development of the Ohio Principal Evaluation System, and the development of rubrics to measure principal performance. The authors believe that this work may be instructive and helpful to other entities that are seeking to upgrade principal performance. (Contains 1 note.)