The advent of the principle of popular sovereignty during the French Revolution inspired an unintended but momentous change in international law. Edward James Kolla explains that between 1789 and 1799, the idea that peoples ought to determine their fates in international affairs, just as they were taking power domestically in France, inspired a series of new and interconnected claims to territory. Drawing on case studies from Avignon, Belgium, the Rhineland, the Netherlands, Switzerland, and Italy, Kolla traces how French revolutionary diplomats and leaders gradually applied principles...