This is an exceptionally sophisticated and wide-ranging book on historical time, the construction of the past, present, and future, and the problem of periodization. Its major thesis is that temporal divisions of history are produced by social actors, including historians, who break up time from their distinct temporal positions. The book inquires about the theoretical underpinning and historical constitution of temporal breaks: the premises sustaining notions of pastness, presentness, and futurity; the relations constructed by these notions between historiography and other fields of knowledge; the specific articulation of shifting and mutually competing temporalities both within and beyond European history; and the political implications of temporal divisions. Throughout the book the breaking up of time is studied as a fundamental political operation. To engage with temporal breaks, the authors contend, is to engage with the historian's contemporary, to negotiate borders that act upon the present, including the border that safeguards the presumed autonomy of the time of history-writing. Focusing especially on the temporality of European modernity, the book invites reflection on the politics of time as articulated through categories of historical totalization imposed on modernity's others. But it also suggests that this imposition gave rise to acts of resistance indicating how historical time defies the analytical categories through which social actors seek to organize and control it. This dialectic of imposition and defiance is made evident through the comparative study of temporal concepts that replace one another, compete with one another in certain historical settings without any of them constituting a final historical representation. It is also traced in the continuing significance of suppressed or “failed” temporalities, which are nonetheless still capable of challenging and qualifying our insights into historical time. The book's key contribution lies precisely in the attempt to intensify this challenge by translating the contradictory constitution of modern temporality into a language of self-critique.