The third of the Three Ritual Halls, the Hall of Preserving Harmony (Baohe dian) was completed in the early fifteenth century. It was first called Hall of Scrupulous Behavior (Jinshen dian), was changed to Establishing Supremacy (Jianji dian), and was finally named Hall of Preserving Harmony— with the implication of preserving the unity of one's inner spirit, and sharing harmony under heaven.
In Ming dynasty (1368-1644) times, before attending a grand ritual or ceremony, the emperor left from his residence in the Palace of Heavenly Purity (Qianqing gong) in the Inner Court and was brought to the Hall of Preserving Harmony to change into ceremonial robes.
In Qing times, the hall served as the wedding venue for the Shunzhi Emperor (r. 1644-1661), and as a temporary residence for him and his successor, the Kangxi Emperor (r. 1662-1722), when the three main halls in the Inner Court were under restoration. Every New Year's Eve and on the fifteenth day of the first lunar month (that is, the full moon), emperors held banquets in the Hall of Preserving Harmony to entertain heads of states, imperial kinsmen, and ministers higher than the second rank. From 1789, every three years the Palace Examination was held here.