There is no fixed categorical term for barbarians in Chinese. Specific groups are identified as “aliens” or “cultural others” through words like Man 蠻, Yi 夷, Rong 戎, and Di 狄, but all four terms can be specific or categorical. It is often said that the us-versus-them formula in Zuozhuan (and early Chinese texts in general) is cultural rather than ethnic, but precise definitions of cultural difference can be elusive. This article begins with a discussion of the historical basis for defining possible differences in socioeconomic and cultural practice and moves to the question of representation. It focuses on three issues: (1) Who is the barbarian? Using Lu's dealings with the eastern Yi domains as case studies, the author explores how representation of cultural others is inseparable from cultural self-definition. Similarities and shared roots seem to have generated the impetus for emphasizing distinctions. (2) Arguments on cultural connections or lack thereof are often built on historical retrospection. Embracing historical ties with barbarians can be a way to resist Zhou dynasty demands, even as using the ancient past to disclaim the status of cultural other can function to assert hegemonic ambition. The author examines the uses of history to manipulate notions of shared roots and radical difference. (3) Since the negative qualities attributed to barbarians come up in speeches, we need to consider the rhetorical context of moralizing otherness. Whether the issue is debates on military strategy, the choice of war or peace, or the etiquette of presenting the spoils of victory, we see how attention to particular motives and circumstances driving historical developments results in a complex and nuanced picture that resists simplistic and moralized formulations of cultural identity and cultural difference.