Legitimacy from Seas: Surveying, Mapmaking, and Cosmology of Manchurian Sea Space during the Early Qing

Abstract This article examines how the Qing empire reconfigured its cosmology of seas – ilan mederi – after 1644 to construct a hybrid framework of imperial legitimacy that integrated Manchu and Chinese worldviews. While pre-conquest Manchu cosmology recognized three seas ( dergi mederi, amargi mederi, julergi mederi ) linked to rivers originating from Mount Changbai, early Qing rulers – especially the Kangxi and Qianlong emperors – reinterpreted these concepts within the structure of Chinese sihai (four seas) thought. Through extensive surveys, mapmaking projects, and the incorporation of coastal tribes, the Qing systematically relocated and redefined maritime spaces such as dergi mederi and julergi mederi , aligning them with the culturally resonant donghai and beihai of Chinese political geography. Ritual reforms, including the establishment of new sea temples and the reorganization of natural worship, further embedded these spaces into imperial ideology. By linking Mount Changbai with Mount Tai and equating Manchuria’s eastern seas with the classical East Sea, the Qing court articulated a unified imperial cosmology that situated Manchu origins within the legitimacy-granting landscape of China proper. This study demonstrates that Qing empire-building relied not only on territorial expansion and administration but also on the deliberate remapping of cosmology, geography, and ritual to fuse two imperial traditions into a coherent ideological order.