The bubonic plague is the measure by which succeeding epidemics have long been measured. Its extreme virulence, horrible symptoms, and indiscriminate victim profile all contributed to making plague the archetypical worst-case scenario. For these same reasons, the plague is also an ideal test case for the thesis that epidemic diseases play a major role in shaping human history. Over the course of its three pandemics, the plague had major economic, religious, cultural and political implications for affected societies. In its wake, religious beliefs and medical practices were questioned, public authorities tested, and the social fabric strained.