In The Greatest Killer, Donald R. Hopkins provides a fascinating account of smallpox and its role in human history. Starting with its origins 10,000 years ago in Africa or Asia, Hopkins follows the disease through the ancient and modern worlds, showing how smallpox removed or temporarily incapacitated heads of state, halted or exacerbated wars, and devastated populations that had never been exposed to the disease. In Hopkins's history, smallpox was one of the most dangerous-and influential-factors that shaped the course of world events.