In the late Qing and early Republican periods, various cosmopolitan ideals were widely and continuously discussed and advocated in China. The ancient Chinese idea of Datong 大同 or Great Unity was revived and debated with renewed vigour and reference to the changes of the times, often incorporating the cosmopolitan ideals of religious, social and ideological movements from the West and elsewhere in Asia. Among the chief promoters were Late Qing Confucian reformers, liberal Christian missionaries, Chinese students abroad and intellectuals of the New Culture movement, and many groups including anarchists, Esperantists, Bahá’ís, Theosophists and redemptive society activists. This is a story that overlaps with, at times converges with and at times diverges from the rise of nationalism. Until now, there has been little research on the religious strands of this cosmopolitan wave. Our project aims to trace the networks, practices and social ideas of religious cosmopolitanism, in the period of transition between the end of the first Sino-Japanese war (1895) and the establishment of the Kuomintang regime in Nanjing (1927). Empirically, it will map the encounters and processes by which religious individuals, networks and organizations from China, other parts of Asia (India, Japan, Iran) and the West connected into an effervescent wave of transnational movements around the notion of Datong and related cosmopolitan ideals. Analytically, it will unpack the content of cosmopolitan discourses within these networks and circulations, interrogating the different meanings of cosmopolitanism as promoted by various actors, and their interface with social, religious and political transformations. Theoretically, the project will contribute to the sociological theory of cosmopolitanism, building conceptual tools for outlining parallel and intertwining histories of cosmopolitanism. Using these empirical, analytical and theoretical tools, the project will explain the reasons for the rise and decline of the influence of religious cosmopolitan ideals during the period of the study. With its Chinese, transnational, religious and historical focus, this case will help to correct the primarily Western-centred and purely secular narratives and theories of cosmopolitanism that lack historical depth and continue to influence much academic and public debate.