The origins of the armed warfare between rebel alliances that spread across China in the late 1960s have long been obscure. This historical puzzle poses two distinct but interrelated questions: first, how and why did rebel factions form, and second, why did armed warfare follow? The authors develop a theory of political orientations as a product of contingent interactions among rebel groups and military units after the collapse of local governments and derive testable implications for the emergence of factional conflict across regions and over time. The authors then extend the theory to link levels of violence to the duration of time that conflicts remained unresolved in localities under military control, implying that violence intensified over time as the anticipated costs of defeat escalated. Both implications are tested with a national data set of 17,319 political events extracted from 2,246 city and county annals.