This website is about the history of the disease known as the plague. The term plague referes to three different diseases: bubonic plague, pneumonic plague, and septicaemic plague. All three plages are caused by the Yersinia pestis bacteria. The largest and most famous outbreak of the bubonic plague was the Black Death in Europe; the epidemic began in 1347. The disease is believed to have originated in central Asia, but there is evidence that it may have developed in ancient Egypt.

Bubonic plague is the most common kind of plague; over 1000 cases are reported annually. It can now be treated with antibiotics, but if left untreated, bubonic plague kills about 50% of its victims. Pneumonic and septicaemic plagues are almost always fatal, with or without treatment.