This episode of "Crash Course World History II," hosted by John Green, explores the profound impact of disease on human history, with a focus on pivotal epidemics like the Black Death and the great dying following the Columbian Exchange. Key concepts include the historical neglect of disease studies due to their nebulous nature and the role diseases played in shaping civilizations by affecting population dynamics and aiding in European dominance. The episode underscores the relevance of disease awareness in the context of historical causation. By connecting past epidemics to modern challenges like antibiotic resistance, the video emphasizes the intersection of global and biological histories in shaping human civilization. Part of the "Crash Course World History II" series.