In 2009, the "Handbook of Research on the Education of School Leaders" was published by the University Council for Educational Administration (UCEA). The chapter discussed in this issue of "Implications," introduces a conceptual model for describing the different kinds of knowledge and the interactions among technical knowledge, artistry, and individual and collective valuation. Specifically, "An Historical Review of Research and Development Activities Pertaining to the Preparation of School Leaders," examines the primary building blocks of professional preparation, the history of their use in educational leadership, and evidence regarding the relative importance and utility of these building blocks in the development of competent practitioners.