The immediate aftermath of a great urban earthquake is a dramatic and terrible event, comparable to a massive terrorist attack. Yet the shocking impact soon fades from the public mind and receives surprisingly little attention from historians, unlike wars and human atrocities. In 1923, the Great Kanto earthquake and its subsequent fires demolished most of Tokyo and Yokohama and killed around 140,000 Japanese: a level of devastation and fatalities comparable with the atomic bombing of Hiroshima and Nagasaki in 1945. But the second event has infinitely more resonance in public consciousness and historical studies than the first. Indeed, most people would be challenged to name a single earthquake with an indisputable historical impact, including even the most famous of all earthquakes: the San Francisco earthquake and fire of 1906. In truth, however, great earthquakes, from ancient times—as recorded by Greek and biblical writers—to the present day, have had major cultural, economic, and political consequences—often a combination of all three—some of which were beneficial. Thus, the current prime minister of India owes his election in 2014 to an earthquake that devastated part of his home state of Gujarat in 2001, which led to its striking economic growth. The martial law imposed on Tokyo and Yokohama after the 1923 earthquake gave new authority to the Japanese army, which eventually took over the Japanese government and led Japan to war with China and the world. The destruction of San Francisco in 1906 produced a boom in rebuilding and financial and technological development of the surrounding area on the San Andreas Fault, including what became Silicon Valley. A great earthquake in Venezuela in 1812 was the principal cause of the temporary defeat of its leader Simon Bolivar by the Spanish colonial regime, but his subsequent exile led to his permanent freeing of Bolivia, Colombia, Ecuador, Peru, and Venezuela from Spanish rule. The catastrophic Lisbon earthquake of 1755—as well known in the early 19th century as the 1945 atomic bombings are today—was a pivotal factor in the freeing of Enlightenment science from Catholic religious orthodoxy, as epitomized by Voltaire’s satirical novel Candide, written in response to the earthquake. Even the minor earthquakes in Britain in 1750, the so-called Year of Earthquakes, produced the earliest scientific understanding of earthquakes, published by the Royal Society: the beginning of seismology. The long-term impact of a great earthquake depends on its epicenter, magnitude, and timing—and also on human factors: the political, social, intellectual, religious, and cultural resources specific to a region’s history. Each earthquake-struck society offers its own particular lesson, and yet, taken together, such earth-shattering events have important shared consequences for the history of the world.