Spanning the years from the Manchu invasion of China to the 1724 prohibition of Christianity by the Yongzhen emperor, this book explains the rise and decline of the missionary enterprise by focusing on the relationship between the Qing ruling class and European Jesuits. Rejecting Gernet’s cultural incompatibility model, Swen focuses on the Manchu institution of booi (household).1 Consisting of masters, servants, and slaves, the Manchu household functioned as a state within a state after the conquest of China. The informal power structure and intimacy between master and bondservant/slave (booi aha) operated alongside and within the Chinese bureaucracy; even powerful ministers from booi status identified themselves first and foremost as nu cai (servant) to their masters, rather than as officials to their emperors. Elaborated during the early years of conquest to integrate war captives and surrendered Ming troops, the booi system was central to the creation of the Han military banners. The banner elites, conversant in both the languages and culture of the Manchu and Han Chinese worlds, became preeminent during the reigns of Shunzi, who took a consort from the Han banners, and Kangxi, his son, whose mother came from the eminent Tong, the most powerful clan of the Han banners.The Jesuits became booi aha when Gabriel Magalhães and Ludovico Buglio, reluctant members of Zhang Xianzong’s rebel army, became war captives of the Manchu, eventually passing into the household of the Tong and released in Beijing. The Jesuits were introduced to the imperial court through Kangxi’s maternal uncles, who were benefactors and sympathizers with Christianity. When they were placed under the Imperial Household Department, they entered the intimate power circle of the booi aha. They helped the fifteen-year-old emperor stage a successful palace coup against the powerful regent Oboi, earning his trust. Three generations of Jesuits would loyally serve Kangxi as military engineers, scientists, and diplomats; the emperor rewarded them with protection and patronage, making his reign a golden age for the Christian mission in China.This situation changed in 1722 when the fourth son of Kangxi ascended the throne in the midst of a succession struggle. A devout Buddhist and meditation master in his youth, Yongzhen refused to acknowledge the Jesuits as his booi aha, removing them from the Imperial Household Department and effectively denying them access to the center of power. Religious differences aside, the Jesuits had failed to cultivate ties to Yongzhen when he was still a prince, instead focusing their attention on two other rival princely pretenders who were purged and persecuted in the new regime. The Jesuit João Mourão, a confidant of the Ninth Prince and a bitter rival of Yongzhen, was sentenced to exile and death; other Jesuits incurred imperial wrath because of their close association with the Sounu family, prominent Manchu elites who had supported Yongzhen’s rivals.This story of historical contingency is constructed on the basis of an impressive knowledge of Chinese and Western sources, and a thorough command of scholarship in two fields—Qing history and the history of Christianity—that often fail to cross-fertilize. Most importantly, Swen has provided logical and satisfactory explanations of the key events affecting the Christian mission in the transition from the Ming to the Qing—the prominence and fall of Adam Schall (a German Jesuit astronomer) and the political background of the Calendar Case; Kangxi’s connections to the Jesuits; the politics of the Chinese Rites Controversy and the papal envoys; the issuance of the imperial certificate for missionaries; and, finally, the fall from grace under Yongzhen. Indeed, the story of the Jesuits at court is reminiscent of the rise and fall of the eminent Han banner Cao family, and the masterpiece written by Cao Xueqin, one of its descendants, The Dream of the Red Chamber, a novel with hundreds of characters—masters, servants, officials, and clerics—narrating the transience of earthly success.