This paper draws on the approach of conceptual historians to explore how Asia emerged as a conceptual space with Afghanistan at its center in the minds and writings of Afghan and Muslim intellectuals in the twentieth century. Reacting to European civilizational divides, transnationally-connected Muslim reformers of the early-twentieth century like the Afghan writer and statesman Mahmud Tarzi (1865-1933) conceived of a broader Asia in which Afghanistan figured prominently. It draws on a variety of sources, including newspapers, articles in translation, geography textbooks, travelogues and colonial archives, to trace the concept of ‘Asia’ and ‘Asianess’ that featured prominently in the work of Tarzi and his interlocutors. Though Japan and China were central to their understanding of this concept, they were not only looking east but also south and west across the transregion of what we call the Middle East and South Asia to connect with and imagine the east and Asia. Through Tarzi and the transregional press, Asia became a galvanizing political framework that shaped material solidarities on the ground in Afghanistan. At the same time, the tensions and contradictions in Tarzi’s vision of Asia, and the political realities facing Afghanistan, led to disillusionment and competing claims about what Asia represented. Rather than receiving this category as fixed, then, a conceptual history of Asia prompts us to examine its various meanings and how they might have informed one another and shaped politics. Beyond shedding light on important intellectual developments, this paper also puts forward conceptual history as a method for thinking about areas studies and writing regional histories. It illustrates the potentials of situating and tracking the development of the geographic terms we use across time and languages, noting how they changed over time, through space. How did our historical interlocutors understand these terms? This kind of conceptual teasing-out helps us to argue that these designations are not natural or inevitable, nor do they purely reside in the realm of the imaginary. Instead, by interrogating these regional conceptualizations we find that they are actively contested, and their various meanings historically informed (and continue to shape) political and economic realities.