This paper examines the emergence of the corporeal turn in International Relations (IR) research on war. It argues that a lack of a sustained ontological investigation leaves open two theoretical gaps, which impedes the development of an embodied theory of war: (1) the core concept of a body and its linkages with war are underdeveloped, and (2) existing research on the embodiment of war slips into discursivism or empiricism. The paper invites the corporeal turn scholarship to bring ontology to the forefront of IR war research and to expand a pool of theoretical resources for analyzing the corporeality of war by turning to existential phenomenology. With the phenomenological concept of the lived body placed at the heart of war ontology, war is conceived as a complex social institution with the generative powers born out of the capacity of the violent politics of injury to disrupt the lived bodies' sense-making and agential capacities, on the one hand, and the potential of individuals and communities to reclaim their interpretive integrity and agency through embodied everyday practices, on the other.