How does one build a centralized bureaucratic state? A dominant view is that wars incentivize rulers to directly extract resources, thereby increasing state capacity. The Chinese empire, one of the earliest states to develop a centralized bureaucracy, can provide useful insights. Using hand-collected data, Joy Chen will present the first systematic evidence on patterns of warfare and state-building in pre-imperial China, which is subsequently used to develop an incomplete contract model for studying ruler's and agent's incentives at war. Her study demonstrates that ownership of land and type of military conflict both affect state-building. External military pressure dampens centralization, as land-owning agents have more to gain from a successful defence, and therefore are more committed. Centralized districts are more aggressive at offense against weak enemies, as non-land-owning agents are more willing to participate in attacks. A decrease in agents' bargaining position also facilitates state-building. Empirical tests and historical examples are consistent with model predictions.