Outside the cities, where land gave way to water and there was no risk of major conflagrations, the authorities used lights to make an unambiguous statement about omnipresent and competent leadership. Maritime lights originated as tools of surveillance but, in the age of the Great Peace, also served as extensions of the state’s authority and of its commitment to economic prosperity. After the signing of the 1850s treaties, however, the Tokugawa maritime lights were erased to emphasize the contrast between the skills of Western engineers and the “slight and unimportant” work of native “artisans.” To recover the history of maritime lights in early modern Japan is to dethrone predominant narratives of technological transfers, decenter the West, and put East Asia at the center. It is, in other words, to rewrite not just Japan’s timeline of progress but also the map of global modernization and to imagine a history of the transforming night with East Asia at the center.