In this sweeping survey of approximately 12,000 years of human history, Barry Buzan aims to build theoretical bridges by making innovative use of well-worn concepts associated with the English School of international relations (IR). Buzan examines continuity and change across the “interpolity,” “transnational,” and “interhuman” domains (9–10), and in so doing, he emphasizes the transitions between eras defined by “hunter-gatherers, conglomerate agrarian/pastoralist empires (CAPE), and modernity” (3). The primary indicator that one is in a new era is substantial change in primary institutions or “deep and relatively durable social principles” such as kinship, (in)equality, territoriality, trade, war, and diplomacy (11). Primary institutions, the constitutive elements of “social structure,” can cause or follow from change in “material conditions” in complex “dialectic” and “multilectic” patterns (23). Territoriality, for example, became a salient institution as climatic conditions changed and incentivized a transition from hunting and gathering to more sedentary lifestyles. This notion that one could claim exclusive possession of some space became more firmly entrenched with the rise of extractive empires, and the transition to modernity amplified this shift as