This article excavates the Philippine nation’s cosmopolitan and transnational Asian intellectual moorings, in order to reconnect Philippine history to that of Southeast Asia, from which it has been historiographically separated. It argues that turn-of-the-twentieth-century Philippine Asianism was crucial to the concept of the Filipino nation that the ilustrados (educated elite) constructed, to the ilustrado-led Propaganda Movement’s political argumentation against Spain, and to the political mobilization and organizing of the Katipunan and the First Philippine Republic. It incorporates the “periphery” into our understanding of Pan-Asianism to correct our exclusively intellectual historical and Northeast-Asia-centric understandings of Pan-Asianism. It shows that the revolutionary First Philippine Republic’s foreign collaboration represents the first instance of fellow Pan-Asianists lending material aid toward anticolonial revolution against a Western power (rather than overthrow of a domestic dynasty) and harnessing transnational Pan-Asian networks of support, activism, and association toward doing so.