This article examines the racialization of urban space in early twentieth-century Bangkok. After a general strike in 1910, the Siamese monarchy represented itself in urban space as the leaders of a sovereign nation with a racial Other in its midst. Rather than create a separate, walled enclave to contain this population, the monarchy drew on a material and rhetorical campaign to develop two interdependent cities with distinct racial identities. One city was a national capital under the authority of the absolute monarchy. The other was a thriving port city populated mostly by "Chinese" migrants and governed by extraterritorial law. Juxtaposing the built environment against its discursive representations, this article argues that the monarchy sought to endow the dual city of Bangkok and its inhabitants with racial characteristics to clarify national belonging, control the political power of the region’s migrant population, and cultivate support for royal urban investments.