This revelatory book charts and explains the impact and consequences of successive pandemics, plagues and epidemics on the course of world history - all through the lens of today's ongoing global experience of COVID 19. Ranging from prehistory to the present day, it first defines what constitutes a pandemic or epidemic then looks at 20 guilty diseases: including cholera, influenza, bubonic plague, leprosy, measles, smallpox, malaria, AIDS, MERS, SARS, Zika, Ebola and, of course, Covid-19. Some less well-known, but equally significant and deadly contagions such as Legionnaires' Disease, psittacosis, polio, the Sweat, and dancing plague, are also covered. The book is ordered chronologically. Each chapter features an explanation and description of epidemiology, sources and vectors, morbidity, mortality, governmental response and reaction, societal response and impact as well as psychological issues where known - and the political, legal and scientific consequences it had or has for each locus at a local and international level. In short - the book explains how each of the events both made and influenced subsequent history in its own way, particularly how each shaped future medical and scientific research and vaccine development programmes. It also examines myths about infectious diseases, the role of the media and social media. Perhaps most importantly, Paul Chrystal asks what lessons have been learnt. Will we be better prepared next time? Because, if one thing is sure, there is going to be a 'next time'.