Siyen Fei's work to date is primarily concerned with the political and cultural activism of sixteenth- and early seventeenth-century Ming dynasty China (1368-1644). Examining the action of wide-ranging historical actors—women, urbanites, and border residents—she engages and expands the new scholarly paradigm of “defiant late Ming energy” that re-visions a society formerly considered submissive to an all-powerful imperium. In particular, her research on gender, urbanization and empire breaks new grounds by exploring how this emerging state-society dynamics drove and shaped unprecedented transformations in Chinese history: A patriarchal system subverted by court-promoted control of female sexuality; an idealized rural empire facing drastic waves of urbanization; a self-proclaimed Han-native Chinese polity destabilized by cross-border migration and resultant de-sinicization. Excavating these paradoxical historical movements, her books uncover fascinating stories about the interplay of structure and agency.