Surrender in warfare has determined the fate of governments, states, and nations. It has reduced powerful commanders to powerless captives and inflicted submission, degradation, and even death on common soldiers held as prisoners of war. It has also led to civilian detainees being grossly mistreated and murdered. However, surrender, prisoners of war, and detainees have rarely been addressed as general phenomena in warfare. Leaving the Fight is then an essential history of the evolution of surrender from the Middle Ages to the present day. John A. Lynn II explores the different forms taken by surrender, from the abject capitulation of armies and states to the withdrawal of forces from military interventions deemed to be unwinnable, such as in Vietnam and Afghanistan. He also considers the fates of prisoners of war and civilians detained by military forces from harsh treatment intended to intimidate foes to attempts to win over hearts and minds.