The Overlord Effect is a historically based leadership review that combines the accounts of Veterans of the Normandy Campaign of World War II and presents a conversation about their experiences with the leadership theories that have become part of today"s conversation on the subject in the military, academics, and business. The Normandy Invasion was one of the most complex and successful military campaigns in history. The preparation for this event took years of preparation and training. It required leaders at every level to demonstrate exemplary leadership in a compressed space and time that called for decisions to be made in an instant, for leaders to act with courage and character, and for both followers and leaders to accomplish any mission regardless of the personal cost. The Overlord Effect takes the snapshots of the critical experiences of leaders at every level of the Allied Invasion Force and reviews their actions and places them into understandable, thought provoking insights that will help leaders in any discipline respond better to challenges. The work also presents Dr. Pierce's theory on Emergent Leadership During Crisis(ELDC), and discusses ways that the leaders and professionals of today can use it to help themselves understand their own leadership experience, as well as to develop future leaders in the workplace.