The phrase “War made the state, and the state made war” is a highly controversial statement in contemporary social sciences. It encapsulates the fundamental hypothesis of the Bellicist Theory, which suggests that war played a crucial role in the process of state formation. The present research argues that the Bellicist Theory can be enhanced and made more logically consistent by examining three intervening variables: tax extraction, centralization, and bureaucratization. The study proposes a set of hypotheses and tests them through a historical case study focused on the European state–formation process from 1300 to 1800.