The revival of interest in the just war theory, sparked in large part by publication of Michael Walzer's Just and Unjust Wars at the end of the 1970s, has generated widespread analysis of the conditions in which recourse to arms can be given some sort of moral warrant. However, most contributions have drawn on the long-standing Western tradition of debate, which has for many centuries been inspired by Christian thinkers, and continues to be informed by Christian moral codes. Other traditions, for examples, Islamic and Confucian thinking have been given some attention. However, their status has been no more than marginal. In these circumstances it is necessary to engage in intensive textual exegesis and analysis of the Confucian classics. Only by digging deep into the tradition is it possible to make sense of its historical significance over centuries. In this spirit, this thesis seeks to provide a Confucian perspective on the just war theory by focusing not on the works to which scholars are usually drawn, but on Gongyangzhuan (--), which was rarely held to have much to add to the just war historical analysis.