Hopkins, now assistant director for International Health of the Centers for Disease Control, was an active participant in the World Health Organization's 1960s eradication program; hence his respect for the devastation wrought by variola rex, and this scholarly, meticulous history. A careful chronology traces the suspected origins of the disease: in all probability, the virus spread from animals to man, most likely at early sites of domestication in Asia or Africa around 10,000 B.C. In time, adaptation to the human host was successful, and the chain of transmission from victim to susceptible person remained unbroken until 1980, when WHO formally announced that eradication was complete. Hopkins' tale centers, however, on how smallpox, as an endemic and frequently epidemic disease, laid waste ruling dynasties and political powers, turned the tide of battles, and (speculatively) changed the course of history. Elizabeth I was spared--and so was Lincoln. But the House of Stuart ended; the Hapsburgs were devastated; French, Swedish, Spanish, and Russian lineagas were decimated. Factors that may have contributed to the death of royalty were of course the heroic measures employed to save them (in contrast to the peasants)--starting with heat treatments, bloodlettings, and purges. Hopkins also provides some sidelights on the history of vaccination and inoculation. The material used in modern vaccines for smallpox, we learn, may be neither cowpox (vaccinia) nor some altered form contaminated with variola, but may be derived from horsepox. A solid addition to the annals of epidemiology, with considerable what-if? and other historical curiosa.