This article attempts to explain the appeal of "terror" in the French Revolution by examining the history of the concept of terror. It focuses on historiographical representations of sovereign powers, whether monarchs or nations, as "terrors" of their enemies. It argues that the term typically connoted majesty, glory, justice and hence legitimacy. Moreover, historiographical depictions of past rulers and nations frequently emphasized the transiency of terror as an attribute of power; they dramatized decline in formulations such as "once terrible." For the revolutionaries, terror therefore provided a means of legitimation, but one that always had to be guarded and reinforced.