The complex, highly problematic, often thorny dynamics of trust and authority are central to the anthropological study of legitimacy. In this book, this sine qua non runs across the in-depth examination of the ways in which healthcare and public health are managed by the authorities and experienced by the people on the ground in urban Europe, the USA, India, Africa, Latin America and the Far and Middle East. This book brings comparatively together anthropological studies on healthcare and public health rigorously based on in-depth empirical knowledge. Inspired by the current debate on legitimacy, legitimation and de-legitimation, the contributions do not refrain from taking into account the impact of the Covid-19 pandemic on the health systems under study, but carefully avoid letting this issue monopolise the discussion. This book raises key challenges to our understanding of healthcare practices and the governance of public health. With a keen eye on urban life, its inequalities and the ever-expanding gap between rulers and the ruled, the findings address important questions on the complex ways in which authorities gain, keep, or lose the public’s trust.