Both relationality and separateness are aspects of our everyday lives. How we engage these phenomena hinges on the particular existential assumptions that we take for granted. Within the discipline of International Relations (IR), both relationality and separateness have informed how global politics is studied and practiced. How states and their relations are conceived has, for instance, varied by the distinct degrees of privilege given to separation and interconnection: from notions of completely autonomous units like billiard balls to always emergent phenomena co-constituted through relations. The plurality of trajectories that inform this Special Issue illustrate how much broader the spectrum of relational engagement can be when we are cognisant of the impact of these existential assumptions on forms of life, knowing, and knowledge production in International Relations. By highlighting a spectrum of relational engagement, we raise important questions about the way the various knowledge frames in IR are acknowledged, legitimised, limited, and reproduced.