This document discusses theories of leadership and how a project manager's leadership style may impact project success depending on the type of project. It outlines early hypotheses that a PM's competence, including leadership style, is a success factor on projects. It presents a research model linking PM leadership competencies to project success, moderated by factors like project type. Initial interviews found that leadership style is more important on complex projects, and different competencies are needed depending on if a project is technical or involves change. Certain competencies like communication skills and cultural sensitivity were seen as important for different project types and contexts.