Conventional typologies of lordship and its relationship with royal power in the territories of the English crown emphasize the precocious distinctiveness of royal power as against noble lordship, with the latter consequentially bound by an essentially restrictive territorialized model. Drawing particularly on the example of the kingship/lordship of the Isle of Man, this article considers the manifestations of sub-kingship from the fourteenth to the sixteenth centuries as a way of understanding the complexity of manifestations of sovereignty in these territories. It assesses the use of royal titles and associated ceremonial and issues such as forms of dating. Also considered are some of the practical manifestations of “sovereign” power, seen in rights associated with justice, taxation, and relations between princes, and in the capacity to exclude the intervention of others in these spheres. From the discussion emerges an understanding of royal power as more variable in its footprint and shared in many spaces by men conventionally seen as part of an undifferentiated aristocracy. The reigns of Henry VII and Henry VIII have usually been seen as the final point at which centralization through the power and authority of the English monarch obliterated any remaining echoes of sub-kingship in the North Atlantic archipelago, ending once and for all the possibility of a shared space between kingship and lordship. In considering the historiography of this moment, and evidence for continuity through Henry VIII's reign, the article raises questions about lordship and its political and cultural boundaries in the late medieval and early modern periods.