Some tenth-century English kings, especially Æthelstan and Edgar, were commonly presented as rulers of Britain. The basic reason for this is that they had a loose but real hegemony over the other rulers on the island. This hegemony did not collapse in subsequent centuries, but English kings were less often described as rulers of Britain. The intensification of royal rule within the English kingdom in the second half of the tenth century made kings’ power inside the kingdom increasingly unlike their power elsewhere in Britain: it consequently became harder to think of Britain as a single political unit.
* I am grateful to Thomas Charles-Edwards, George Garnett, Rory Naismith, Alice Taylor, Chris Wickham and Alex Woolf for comments on drafts, and to Nick Karn for supervising the undergraduate dissertation in which I first explored some of the themes of this article.