My dissertation offers a dynamic, relational explanation of the emergence of mid-19th century rebellions in the Qing Empire of China—the bloodiest insurgent civil war in human history. This turbulent era witnessed the formation of widespread and protracted uprisings, including not only the landmark Christian-inspired Taiping Rebellion but also a conjunction of sectarian, ethnic, and religious revolts. Theoretically, my thesis moves beyond the structural, eventful, and endogenous models, and further develops the dynamic model that has been emerging in the field of contentious politics and historical sociology. I employ multiple methods—including subnational and sequential comparison—to analyze a large volume of primary sources such as internal government communications, diaries of officials, records of rebels, memoirs of missionaries, and local sources. My dissertation makes a central theoretical contention: that revolutions and rebellions usually emerge from processual interactions among multiple organizational actors rather than being determined by pre-existing structural conditions or static, categorical identities (i.e., class, religious, or ethnic identities). This contention contains three interrelated claims: first, insurgent actions and events are often produced in reaction to the revolutionary process rather than preexisting structures; second, the emergence of rebellions is the result of dynamic interactions among relational actors; third, the unfolding of rebellions is thus sensitive to temporalities, albeit in patterned ways. By elaborating these claims, my dissertation makes distinctive contributions to the understanding of the origins and processes of large-scale movements. In the empirical analysis, I focus on a few critical episodes during this rebellious wave, including: the abrupt transformation of the Taiping movement from an indigenous Christian society to a revolution, the divergence of initially defensive elite militias into rebels and repressors, the crystallization of Muslim mobilization in distinct directions across three regions, and the frequent defection from and division of originally coherent coalitions. Structural conditions and pre-existing identities offer a limited explanation of these phenomena. Instead, rebellious mobilization and development often unfolded as short-term, unintended outcomes of iterative interactions among key actors—including central and local state actors, militia commanders, communal elites, and religious leaders—who often employed emerging organizational frameworks to respond to their local rivals, competitors, and patrons in changing situations. In a nutshell, by uncovering underlying mechanisms from complicated historical processes, the dynamic, relational model proves crucial to the unpacking of puzzles about the emergence, transformations, and divergence of these consequential movements.