How did conflicting legitimation narratives in early modern East Asia coexist despite the tensions their mutually exclusive claims generated? Prevailing accounts understand authority to be legitimised through narratives emphasising hierarchical delegation or autonomous production. In practice, both existed simultaneously. Existing accounts in International Relations (IR) suggest conflicting legitimation narratives should produce instability at best and hostilities at worst. Yet conflicting narratives endured over the long term in this period. I argue conflicting legitimation narratives were performed by actors in early modern East Asia within separate locations, allowing contradictory claims around the nature of their authority to coexist. This is seen through the contemporaneous phrase wài wáng nèi dì or ‘emperor at home, king abroad’. To demonstrate this, I introduce the segmentation of space as a concept. Producing an inside/outside dynamic, East Asian actors performed their authority through autonomously produced legitimation narratives inside while acknowledging hierarchically delegated narratives as the basis for authority outside. I identify this process of segmentation operating at both the state and the region level. Both early modern Japan and Vietnam demonstrate how East Asian thinking and practices on spatial organisation were adapted across all levels of the system. Thus, conflicting legitimation narratives could endure without converging on shared understandings.