Book excerpt: Between 1800 and 1920, the territory and influence claimed by Western empires came to cover a larger portion of the globe than at any time before or since. Why and how did this happen? What were the consequences of this unprecedented scramble for dominion? What methods have historians used to understand the increasingly large and structurally complex Western empires that emerged across the long 19th century? In this fifth volume, A Cultural History of Western Empires in the Age of Empire, we trace these questions across a period bookended by two devastating global wars. The forces that enabled unparalleled Western expansion were likewise violent. Often no less traumatically, the phenomenon was also one of cultural exchange and negotiated identities in which both colonized and colonizer were repeatedly made and remade. As cultural historians, we locate the power struggles of empire as much in identity and ways of life as in the movement of armies or the signing of treaties. New technologies of communication, transport and warfare brought an 'Age of Empire' into existence for the West. But it was equally grounded in new ways of thinking about human difference and new beliefs about the state's power to intervene in the most intimate domains of human behavior.