In the last month of 1739, the third of the Manchu rulers, the Qianlong emperor (r. 1736-1795), ordered the compilation of a treatise on medicine "to rectify medical knowledge" throughout the empire. By the end of 1742, eighty participants chosen from several offices within the palace bureaucracy based in Beijing completed the Golden Mirror of the Orthodox Lineage of Medicine, the only imperially commissioned medical text the Qing government's Imperial Printing Office published. The Golden Mirror represents both the limitations in the power of the Qianlong emperor and the dominance in the Manchu court of Chinese scholarship from the Jiangnan region during the first decade of his reign. Chinese scholars participating in the compilation of the Golden Mirror fashioned a medical orthodoxy for the empire in the mid-eighteenth century from regional trends in scholarship on history and the classics centered in the Jiangnan region since the sixteenth century. The Golden Mirror is an illuminating example of how medical scholars participated in the formation of evidential scholarship in early-modern China and why Manchu patronage, southern Chinese scholarship, and medical orthodoxy coalesced in the imperial court of the Qianlong emperor.