Book excerpt: Introduction: The invisible empire -- The discourse of ethnicity -- Agriculture and foodways -- Vernacular languages -- Marking territory : the militarization of the Huai frontier -- Making hierarchy : garrison, court, and the structure of Jiankang politics -- Managing prosperity : the political economy of a commercial empire -- The vernacular repertoire -- The Sinitic repertoire -- The Buddhist repertoire : the era of pluralist patronage -- The Buddhist repertoire : Jiankang as theater state -- Conclusion: Re-orienting East Asian and world history.