Despite the currency of the ‘spatial turn’ in history more generally, the history of political thought has not yet turned its attention to the concept of space in any systematic way. The natural rights tradition seems particularly resistant to such a reading. The present article seeks to uncover how notions of space and spatial relations intersect with law and legal relations in a key text of that tradition. I argue that space is central to the way in which Grotius in De iure belli ac pacis understands political and inter-political phenomena and that his concept of moral reasoning is specifically geared to accommodate this dimension.