What's the common bond shared by leaders as diverse as Ernest Shackleton, Abraham Lincoln, Dietrich Bonhoeffer, Rachel Carson and Frederick Douglass? Each succeeded in the face of overwhelming odds. And they did so while battling self-doubt, personal tragedy and fear of failure. In short, they were far from what we think of when we imagine confident, strong-willed leaders. Yet each offers powerful lessons in what it takes to triumph in crisis. Expanding on her series of popular profiles written for The New York Times , historian and Harvard Business School professor Nancy Koehn examines the journeys of these fascinating leaders through in-depth, personal portraits. She reveals the many ways they made tough choices that allowed them to persevere and ultimately succeed.  And she provides a new framework for leadership —one that values conviction, humility, resilience and the ability to adapt above all else.