 There are a number of historical theories which have presented arguments about territory that have been relatively neglected in the scholarship on these theories, which has tended to focus on other aspects of their argument. Three key traditions are the natural law tradition, in particular Grotius and Pufendorf; the social contract tradition, and particularly Locke, who offered a theory of political obligation and a justification for limited constitutional government; and the justice tradition, associated with Kant, which identifies the state with the achievement of justice. None of these offered a complete theory of territory, but they did, in the course of theorizing the state and the international order, connect territory in crucial ways to their overall argument, such that it is extremely useful to focus on how they conceptualized territory, how they argued for it, and how it was related to other key elements in their political theory. Contemporary theories, which will be discussed in sect. 3, mainly build on these earlier theories.