This work examines the effect of Churchill"s strategic notions, positions and decisions on the course of the two World Wars, and goes on to test the reliability of Churchill"s own works about the two Wars. The book focuses on the highest level of military decision making where strategy becomes a function of political judgement, though there is some discussion of tactical and operational details. The book traces the development of Churchill"s strategic thought from his early army career, through his role as a decision maker in World War I, up until the outbreak of World War II and his appointment as Prime Minister. It then seeks to show how the conduct of World War II was based on principles and lessons learnt during the earlier part of his career.