Beijing has been the seat of political power in China for more than seven centuries, since Khubilai Khan established the "Great Capital" (Dadu) of the Yuan dynasty (1271–1368) there in 1274. Although little of Khubilai's palace survives, the present Forbidden City—the symbolic center of imperial authority—was begun by the Yongle Emperor (r. 1406–24), the third ruler of the Ming dynasty (1368–1644); was largely rebuilt and reworked during the ensuing Manchu Qing dynasty (1644–1911); and, since 1925, has been restored and maintained as the Palace Museum.
Symmetrically laid out along a central north-south axis and named the "Purple Forbidden City" after the Purple Luminous constellation (which has Polaris, the North Star, at its center), the complex symbolizes the ritual centrality of the emperor as the ruler of a balanced, stable, and hierarchically ordered world.
The principal audience and residential halls are all arranged along the central axis, which is more than a half-mile long. A similar array of axially aligned buildings, the Tranquility and Longevity Palace, was constructed for the Qianlong Emperor (r. 1736–95) in the northeast corner of the Forbidden City in anticipation of his eventual retirement. It is there that a two-acre plot of asymmetrical pavilions, rockeries, and plantings was created as the luxurious garden retreat that is the subject of this exhibition.