For the last twenty years, an “emotional turn” in the study of history has been gathering momentum, building on other disciplines. Fifty years ago, neuroscientists started to trace brain activity that linked reason and emotion. Psychologists—early pioneers in the study of emotions—had already begun investigating the power and universality of emotional drivers. Social scientists took notice first, and historians have followed. The upshot to this trajectory is that the study of emotions in history has become fundamentally interdisciplinary; as a result, historians have become the new pathbreakers.