This unique, interdisciplinary book critically examines the important roles that witness accounts from healthcare professionals have played in testifying to historical instances of genocide, mass killing, epidemic disease, and natural disaster over the past century. Knowledge and perceptions of many major disasters – natural and human-made – have been shaped by witness accounts provided by doctors, nurses, and other medical practitioners. Bookended by two key events in the modern history of medicine, the Holocaust and the COVID-19 pandemic, this original volume engages with topics, including the atomic bombing of Hiroshima and Nagasaki, the 2010 Haiti Earthquake, and the Korean War. Drawing on a multidisciplinary selection of leading scholars and healthcare practitioners and discussing a wide range of media, its emphasizes mental and physical health, highlights the ethical challenges and moral stresses these terrible events can pose, and assesses the ways in which the testimonies of healthcare professionals are qualitatively different from other forms of witness. This wide-ranging, volume explores issues and themes relevant to medical humanities, history of medicine, peace and conflict studies, narrative medicine, humanitarian healthcare, healthcare ethics, trauma studies and global health. It is an essential contribution for all healthcare practitioners, aid workers and academics interested in these fields.