The representation of time in historiographical narratives reveals important conceptions about origin, continuity and change, and the perceived links between the past, present and future in a society. Through temporal structures of meaning such as genealogy, political power can be explained, legitimized and reinforced in narratives of the origin and history of a people and its rulers. The aim of this article is to investigate the construction of political time in two fifteenth-century Old Swedish narratives, Prosaiska krönikan and Lilla rimkrönikan. These chronicles constitute some of the first attempts to write continuous histories of the Swedish realm and its rulers from time immemorial. While the two chronicles share basic temporal structures, their different narrative forms also involve shifting emphases in their representation of a political time that functions as the basis for claims to a precedence of power and authority in relation to the other Scandinavian kingdoms. By considering temporal structures of meaning in the two chronicles, light can be shed on the political and ideological utility of history writing in late-medieval Sweden.