How much conflict was there in early modern East Asia? What was the general pattern of interaction between China and other East Asian polities? Although seemingly straightforward, these questions are surprisingly difficult to answer in any systematic manner. Besides language barriers and the struggle with rich historical narratives, a formidable obstacle facing historians and social scientists is that there are almost no systematic data available. Given this, it is extremely difficult to make causal arguments in an empirically falsifiable manner and evaluate competing claims when it comes to the study of historical international relations of East Asia. In collaboration with David Kang, Meredith Shaw, and Dat Nguyen, we have created an extensive dataset of war and other violence in historical East Asia to fill this lacuna. Comprising over 14,00 entries, the dataset follows modern social scientific standard and utilizes language sources of Chinese, Korean, and Vietnamese.